SF 



Issued April 2 4, 1911. 



U. S. DEPARTMENT OF AGRICULTURE, 

BUREAU OF ANIMAL INDUSTRY.— Bulletin 134. 

A. D. MELVIN, Chief of Bureau. 



THE ESTIMATION OF TOTAL SOLIDS IN 
MILK BY THE USE OF FORMULAS. 



BY 

5 R. H. SHAW, 
Dairy Chemist, Dairy Division, 
AND 

C. H. ECKLES, 

Professor of Dairy Husbandry, University of Missouri. 







WASHINGTON: 

GOVERNMENT PRINTING OFFICE. 
1911. 




Pass SF £i_l 

Book : 






Issued April 21, 1911. 

U. S. DEPARTMENT OF AGRICULTURE, 

BUREAU OF ANIMAL INDUSTRY.— Bulletin 134. 

A. D. MELVIN, Chief of Bureau. 



THE ESTIMATION OF TOTAL SOLIDS IN 
MILK BY THE USE OF FORMULAS, j^ 

79 2- 



BY 



R. H. SHAW, 

Dairy Chemist '; Dairy Division , 
AND 

C. H. ECKLES, 

Professor of Dairy Husbandry \ University of Missouri. 




WASHINGTON: 
GOVERNMENT PRINTING OFFICE. 

1911. 



n 



^ 



&A 

^ 



THE BUREAU OF ANIMAL INDUSTRY. 



Chief: A. D. Melvin. 
Assistant Chief: A. M. Fakrington. 
Chief Clerk: Charles C. Carroll. 

Animal Husbandry Division: George M. Rommel> chief. 
Biochemic Division: M. Dorset, chief. 
Dairy Division: B. H. Bawl, chief. 

Inspection Division: Rice P. Steddom, chief; R. A. Ramsay, Morris Wooden, 
and Albert E. Behnke, associate chiefs. 

Pathological Division: John R. Mohler, chief. 
Quarantine Division: Richard W. Hickman, chief. 
Zoological Division: B. H. Ransom, chief. 
Experiment Station: E. C. Schroeder, superintendent. 
Editor: James M. Pickens. 

DAIRY DIVISION. 

B. H. Rawl, Chief. 

Helmer Rabild, in charge of Dairy Farming Investigations. 

S. C. Thompson, in charge of Dairy Manufacturing Investigations. 

L. A. Rogers, in charge of Research Laboratories. 

George M. Whitaker, in charge of Market Milk Investigations. 

Robert McAdam, in charge of Renovated Butter Inspection. 

2 



LETTER OF TRANSMITTAL. 



U. S. Department of Agriculture, 

Bureau of Animal Industry, 

Washington, D. C, November 26, 1910. 

Sir: I have the honor to transmit herewith, and to recommend for 
publication in the bulletin series of this bureau, a manuscript entitled 
"The Estimation of Total Solids in Milk by the Use of Formulas," 
by R. H. Shaw, of the Dairy Division of this bureau, and C. H. Eckles, 
of the Missouri Agricultural Experiment Station. The experimental 
work herein described forms a part of the investigations concerning 
milk which are being conducted at the Missouri station in cooper- 
ation with this bureau. 

Owing to the necessity for some more rapid method of calculating 
the solids in milk than the usual laboratory procedure, the estimation 
of these constituents by means of formulas has been a common dairy 
practice for some years; and while a certain amount of error was 
known to exist in such calculations, it was assumed to be small 
enough to be negligible for most practical purposes. Inasmuch, how- 
ever, as a number of formulas are in use, each differing slightly in 
results from the others, it became a question of some importance to 
determine which of them was the most accurate. 

With the object of solving this problem the authors have made 
searching tests under exacting conditions of several of the best known 
formulas, and have in addition devised an improved lactometer 
which, with a table based upon the results of the work described in 
this bulletin, is believed to furnish a method which is more nearly 
accurate than any at present in use. 
Respectfully, 

A. D. Melvin, 

Chief of Bureau. 

Hon. James Wilson, 

Secretary of Agriculture. 



CONTENTS. 



Page. 

Introduction 5 

Synopsis of formulas in vogue 6 

Experiments to compare the accuracy of existing formulas 7 

Methods of calculation and terminology 8 

Method of sampling 8 

Method of determining specific gravity and total solids 9 

Comparison of the formulas with gravimetrically determined results 9 

The specific gravity of milk solids 11 

Experiments to determine accuracy of lactometers 15 

Tests of Babcock formula and new lactometer with individual milkings 17 

Effect of temperature on specific gravity of milk 19 

Recknagel's phenomenon, 20 

How to use the modified lactometer and table 21 

Method 21 

Directions for using the table • 22 

Summary and conclusions 25 

Appendix 26 



ILLUSTRATION. 



Page. 

Fig. 1. Lactometer designed for use in experimental work 16 

4 



THE ESTIMATION OF TOTAL SOLIDS IN MILK BY THE 

USE OF FORMULAS. 



INTRODUCTION. 

Various formulas have been in use for a number of years as a 
means of determining the total solids in milk when the specific 
gravity and percentage of fat are known. This rapid estimation of 
the total solids is a useful and convenient method for purposes where 
exactness is not required. Among the more common uses that have 
been made of this method is the preliminary examination of market 
milk by inspectors and the detection of adulterations at cheese 
factories. 

Kecently certain organizations representing the dairy breeds of 
cattle have considered the advisability of reporting the percentage 
of total solids as well as of fat in making official tests of individual 
cows. It therefore became a question as to whether the determina- 
tion of the total solids by means of the formulas and the instruments 
in common use for finding the specific gravity was feasible and accu- 
rate enough. 

In view of this question Mr. Ed. H. Webster, then Chief of the 
Dairy Division of the Bureau of Animal Industry, requested the 
authors to take up the problem with the view of testing the accuracy 
of the estimation of total solids by the several formulas in common 
use and to suggest improvements looking toward greater accuracy 
in finding the specific gravity without making the determination 
impracticable for use by such men as usually have charge of official 
testing. 

For the present purpose milk may be regarded as composed of fat 
and milk plasma, the latter being made up of water and the various 
milk solids not fat, such as the proteins, sugar, ash, and other solids. 
Fat, having a specific gravity less than water, has the effect of lower- 
ing the specific gravity of milk, while the plasma solids, having a 
specific gravity greater than water, have the effect of raising it. It 
is clear, then, that a relation exists between the specific gravity of 
milk and its percentage of fat and solids not fat. The various for- 
mulas for calculating total solids or solids not fat, when the other 
two factors are given, are based upon this relation. 

It is not the purpose of this bulletin to bring out a new formula 
or to suggest modifications or revisions of those already in use. The 

5 



6 ESTIMATION OF TOTAL, SOLIDS IN MILK. 

main objects of the investigation herein reported were: (1) To com- 
pare the percentages of total solids calculated by means of certain 
formulas in general use with those obtained gravimetrically in the 
laboratory; (2) to test under more exacting conditions the formula 
which yields results closest to gravimetrically determined total 
solids, and (3) to devise a new or modify an existing lactometer with 
which the specific gravity may be more accurately determined. 

The authors desire to acknowledge their indebtedness to A. E. 
Perkins and G. C. Payne, of the Dairy Division and Missouri Agri- 
cultural Experiment Station, for assistance rendered in obtaining 
the data included in this bulletin. 

SYNOPSIS OF FORMULAS IN VOGUE. 

Behrend and Morgen * published in 1879 the first formula of which 
there is any record which attempts the calculation of total solids from 
the specific gravity and the percentage of fat. They were closely 
followed in the same year by Clausnitzer and A. Mayer, 2 who pub- 
lished another formula. These two formulas were, however, based 
on inaccurate data and have since been abandoned. Since that time 
numerous other formulas have been proposed, among them being 
one by Fleischmann and Morgen. 3 In this formula the specific 
gravity of butter fat was assumed to be 0.94. This was changed to 
0.93 by Fleischmann, 4 and the formula thus revised is still in general 
use and is one of those compared in this investigation. Hehner's 5 
formula appeared in 1882, that of Halenke and Moeslinger 6 in 1886, 
and that of Hehner and Richmond 7 in 1888. The latter formula 
was revised in 1894 by Richmond, 8 and the revised form is known 
as Richmond's new formula. Babcock 9 published his formula in 
1891, but changed it four years later. 10 

Comparisons of the various formulas with gravimetrically deter- 
mined total solids have appeared from time to time. Such compari- 
sons were made in 1889 by Woll, 11 who worked with the Fleischmann 
and the Hehner and Richmond formulas. In his conclusions, which 
are in favor of the Fleischmann formula, he states that it may 

1 Journal fur Landwirtschaft, Band 27, p. 249. Berlin, 1879. 

2 Forschungen auf dem Gebiete der Vieh-haltung und ihrer Erzeugnisse, p. 265. Bremen, 1879. 

3 Journal fur Landwirtschaft, Band 30, p. 293. Berlin, 1882. 

4 Journal fur Landwirtschaft, Band 33, p. 251. Berlin, 1885. 

5 Analyst, Vol. VII, p. 129. London, 1882. 

eChemiker-Zeitung, Jahrg. 10, semester 1, Chemisches Repertorium, p. 8. Cothen, 1886. 
i Analyst, vol. 13, p. 26. London, 1888. 

8 Proceedings of the Eleventh Annual Convention of the Association of Official Agricultural Chemists, 
Washington, D. C, Aug. 23-25, 1894, United States Department of Agriculture, Bureau of Chemistry» 
Bulletin 43, p. 181. 

9 Eighth Annual Report of Wisconsin Agricultural Experiment Station, 1891, p. 292. Madison, 1892. 

io Twelfth Annual Report of Wisconsin Agricultural Experiment Station, 1895, p. 120. Madison, 1896. 
« Agricultural Science, vol. 3, p. 129. State College, Pa., 1889. 



EXPERIMENTS WITH EXISTING FORMULAS. 7 

be used to advantage for calculation of total solids if the specific 
gravity of milk is taken at 15° C. 

In the early nineties the Association of Official Agricultural 
Chemists made some comparisons of the Fleischmann, the Hehner and 
Richmond, the Babcock (original), and the Richmond formulas. 
Their results are published in the proceedings of their tenth 1 and 
eleventh 2 annual conventions, and in commenting on the same they 
state that the Hehner and Richmond formula gave figures which 
compared best with those obtained gravimetrically. 

EXPERIMENTS TO COMPARE THE ACCURACY OF EXISTING 

FORMULAS. 

In a cooperative experiment between the Missouri Agricultural 
Experiment Station and the Dairy Division of the Bureau of Animal 
Industry, United States Department of Agriculture, a study was 
made of the changes in chemical composition which milk undergoes 
during the natural period of lactation. Among many other factors 
the specific gravity and the percentages of fat and total solids were 
determined under controlled conditions. These determinations were 
made on 12 animals through one entire lactation period, and on 2 
of the animals through two entire lactation periods. Having these 
data at hand, it became purely a matter of substitution to apply the 
figures obtained for the specific gravities and the percentages of fat 
in some of the most frequently used formulas for determining total 
solids when these two factors are known, and comparing the figures 
so obtained with the corresponding percentages of total solids deter- 
mined gravimetrically. As stated in the introduction, several 
formulas have been published, but perhaps of these the four most used 
are those derived by Babcock (revised), Hehner and Richmond, 3 
Richmond, and Fleischmann. In the general lactation experiment 
above referred to the samples were taken from the very beginning of 
the lactation period to the very end of the period, but since the pur- 
pose of this investigation is to show the application of various 
formulas in determining total solids in normal milk, it was thought 
best to exclude the extremes from the comparisons, and so the figures, 
except when otherwise stated, refer to milk of normal composition. 

The 12 animals used in the investigation included 3 each of 4 
breeds — Holstein-Friesian, Jersey, Ayrshire, and Shorthorn. Accord- 
ing to the general plan these animals were kept on a uniform ration 

1 Proceedings of the Tenth Annual Convention of the Association of Official Agricultural Chemists, 
Chicago, Aug. 24-26, 1893. TJ. S. Department of Agriculture, Bureau of Chemistry, Bulletin 38, p. 107. 

2 Proceedings of the Eleventh Annual Convention of the Association of Official Agricultural Chemists, 
Washington, D. C, Aug. 23-25, 1894. U. S. Department of Agriculture, Bureau of Chemistry, Bulletin 
43, p. 182. 

3 The formula of Hehner and Richmond was compared in the same way as the others, but the results 
were so nearly identical with those of the Babcock formula that it was thought best to omit them from 
this bulletin. 



8 ESTIMATION OF TOTAL SOLIDS IN MILK. 

throughout the entire milking period in order to eliminate possible 
changes in the composition of the milk due to feed. This ration con- 
sisted of alfalfa hay, three-fifths, the other two-fifths being made up 
of corn 8 parts, bran 1 part, and oats 1 part. The ratio between 
the hay and the grain was kept the same at all times. The cows were 
kept in the barn during the night and in an adjoining lot having no 
grass or other food during the day. The animals were fed and 
milked twice daily, at 5 a. m. and 4 p. m. The ration served to keep 
the animals in good condition, and the production of milk was about 
typical of the breeds, although not equal to that produced previously 
by the same animals when opportunity was given to vary the ration 
and adapt it to the needs of the individual. 

METHODS OF CALCULATION AND TERMINOLOGY. 

In preparing the mass of calculations involved in this bulletin free 
use was made of tables prepared by the several authors of the for- 
mulas. In calculating and averaging percentages the rule followed 
was to discard the third decimal figure when it was less than 5, and 
to increase the second by one when it was 5 or more. This will 
explain what may appear to be discrepancies in some of the tables. 

To be strictly accurate the average of a series of specific-gravity 
determinations must be made by first converting the result for each 
determination into terms of specific volume. These figures may then 
be averaged in the usual manner and the resulting average converted 
back into terms of specific gravity. The error introduced, however, 
by simply dividing the sum of the specific gravities by the number of 
determinations was so very small that the averages given in this bulle- 
tin were all made in this way. 

In order to avoid confusion, the term " plasma" is employed to 
designate whole milk minus the fat; "plasma solids" to designate the 
solids in milk minus the fat; and " total solids " the solids including the 
fat. 

METHOD OF SAMPLING. 

The milk was weighed after milking and mixed by pouring it back 
and forth from one pail into another. A sample of about 1 quart 
was placed in a glass jar bearing the number of the cow and the num- 
ber of pounds for that particular milking, and delivered to the 
laboratory. A certain number of cubic centimeters per pound were 
then measured out and placed in a covered receptacle to make up a 
composite sample to represent a week's milk from that particular 
cow. Formaldehyde was added in the proportion of 1 part to 5,000 
to preserve the sample. At the end of the week the composite sample 
was thoroughly mixed and a subsample taken for chemical analysis. 



GRAVIMETRICALLY DETERMINED RESULTS. 9 

METHOD OF DETERMINING SPECIFIC GRAVITY AND TOTAL SOLIDS. 

The specific gravity of the milk was determined at 15° C. by means 
of a Westphal balance. 

The determinations of fat and total solids were made by the Bab- 
cock asbestos method. A woolly asbestos was used in perforated 
copper cylinders, and the determinations were conducted according 
to the official method as described in Bulletin 107 (revised) of the 
Bureau of Chemistry, United States Department of Agriculture. 

COMPARISON OF THE FORMULAS WITH GRAVIMETRICALLY 

DETERMINED RESULTS. 1 

The main table showing the comparisons of the three formulas in the 
individual cases is found in the appendix. Tables 1, 2, and 3, imme- 
diately following, are made up of averages from figures in the main 
table. No explanation will be needed to show how the various 
figures are obtained. A study of the tables will show that in the case 
of every cow, regardless of breed or individuality, the Babcock for- 
mula yielded results closest to those obtained by gravimetric deter- 
mination of the total solids. A comparison of the results obtained by 
the Babcock formula with the gravimetric results shows that 256, or 
59.53 per cent, of the 430 cases agree within 0.25 per cent, and that 
389, or 90.46 per cent, agree within 0.5 per cent. Using Richmond's 
formula in the same way, 360, or 83.7 per cent, of the cases fall within 
the prescribed limit of 0.5 per cent. Likewise Fleischmann's formula 
shows 309 cases of agreement, or 71.85 per cent. With the Hehner 
and Richmond formula, the figures of which are omitted from this 
publication for reasons previously stated, there was a similar agree- 
ment in 387, or 89.99 per cent, of the cases, showing that this formula 
yields results practically identical with those derived from the Bab- 
cock formula. 

A' study of Table 4 will reveal the fact that the calculated figures 
from the Babcock formula do not differ from the gravimetric figures 
in any uniform direction, but that the plus and minus differences 
nearly counterbalance. That they do nearly counterbalance is shown 
conclusively in Table 3, where it will be seen that the average figure 
for the calculated solids for the entire series of comparisons differs 
only 0.07 per cent from the corresponding average figure determined 
gravimetricaily. 

i In some cases in this bulletin the specific gravities are given in terms of Quevenne degrees. These 
degrees, of course, refer to the arrangement of the scale on the style of the lactometer known as the Quevenne 
lactometer. Quevenne degrees are converted into specific gravity by dividing by 1,000 and then adding 
1 to the quotient. For example, if the Quevenne reading is 32.5 the specific gravity is 1.0325. 

76857°— Bull. 134—11 2 



10 



ESTIMATION OF TOTAL SOLIDS IN MILK. 



Table 1. — Number of instances where the total solids calculated by the Babcock, Richmond, 
a?id Fleischmann formulas lie within stated limits of the gravimetrically determined total 
solids. 

[Number of cases.] 





Cow No. 


Between 
and 0.24 
per cent. 


Between 

0.25 and 0.49 

per cent. 


Between 

0.50 and 0.74 

per cent. 


Between 
0.75 and 1 
per cent. 


Over 1 per 
cent. 




M 
o 

o 
o 
Xi 
a 
pq 




o 
o 

2 


a 

o3 
o 

|3 


M 

o 
o 

03 

pq 


o 

o 


a 

03 
o 

co 

'3 

5 


o 
o 
o 

a 
pq 


a 

o 

s 


03 

O 
_co 

'3 


M 
o 
o 
o 

,Q 
03 

pq 


'a 
o 

1 

o 

5 


a 

a 

03 
o 

CO 


o 
o 
o 

.a 

03 

pq 


a 

o 

1 

s 


a 

a 

03 

1 
O 
co 


4 


20 
15 
15 

50 

30 
20 
30 

80 

12 
14 
17 
23 
9 

75 

23- 

21 

7 

51 

256 


15 
14 

18 

47 

26 
17 
26 

69 

15 
14 

14 
22 

8 

73 

21 

17 

3 

41 

230 


10 
10 
14 

34 

16 
16 
23 

55 

15 

8 

11 

16 

4 

54 

14 

11 

3 

28 

171 


4 
16 
16 

36 

12 
15 

6 

33 

11 
9 

5 

12 l 

2> 

39 

11 
7 

7 

25 
133 


6 

9 

11 

26 

13 

15 
10 

38 

9 
7 
9 
11 
2 

38 

10 
10 

8 

28 
130 


9 

7 
11 

27 

17 
12 
13 

42 

5 
9 
8 
12 
6 

40 

14 

10 

5 

29 

138 


1 
6 
2 

9 

3 
5 
9 

17 

3 

1 
3 
1 
1 

9 

1 
1 

2 
37 


4 

12 

4 

20 

6 

7 
6 

19 

1 
3 
2 
3 
1 

10 


4 

11 

8 

23 

10 

7 
2 

19 

5 
6 
4 
7 
1 

?3 






2 
9 








99 




2 








118 










Total for breed 


1 
.... 

2 


2 

1 
1 
3 

5 

1 


11 

2. 
5 

7 

14 

1 
1 
2 
1 

1 

6 

2 
1 




— 


— 


205. 




1 


1 


9 


206 




209 


1 


1 

2 


1 




Total for breed 


3 


300. 






300. 










301. 












301 


1 
1 


.... 

2 

1 


.... 


1 


1 


302 






Total for breed 


.... 


1 


1 


400. 






3 5 

2 7 

3 1 6 

8 1 18 




402. 










403. 














Total for breed 


3 


1 

10 


3 
34 










Total cases 


57 


83 


1 


3 


4 



Table 2.— Data of Table 1 ex-pressed in percentages. 
[Per cent of cases.] 





Between and 
0.24 per cent. 


Between 0.25 

and 0.49 per 

cent. 


Between 0.50 

and 0.74 per 

cent. 


Between 0.75 

and 1.00 per 

cent. 


Over 1 per 
cent. 


Cow No. 


M 

Q 

O 
O 

■8 

pq 


■d 

el 
o 

o 

s 


d 

03 

a 

to 

'3 

5 


M 
o 
o 
o 

03 

pq 


o 
o 


pj 

o 
. M 

5 


,i*5 
o 
o 
o 

03 

pq 


«6 

o 

o 

s 


a 

O 

M 

'3 


M 

o 
o 
« 

03 

pq 


d 

o 

o 


a 

03 

S 

o 

"3 


& 
o 

o 


TS 

PI ' 

a 

s 

o 

s 


pi 
a 

03 

H 

O 
co 

|3 

— 


4 , 


80 

40-. 54 
45. 45 


60 

37.84 
54.55 


40 


16 


24 

24.32 

33.34 


36 

18.92 

33.34 


4 

16.22 
6.06 


16 


16 






8 








99 


27. 03 43. 24 
42.42;48.49 


32.43 29.73 
12.12 24.24 




5.41 


24. 39 








118 

























Per cent for breed. 


52.64 


49.48 


35.80 37.89 27.37 


28.41 


9.47 


21.05 


24.21 




2.1011.58 








205 


63.83 

50 

65.21 


55.33 34.04 
42. 50 40 


25. 54 27. 66 
37. 50 37- 50 


36.16; 6.38 
30 12. 50 
28.2619.56 


12.76 
17.50 
13.05 


21.27 

17.50 

4.35 


2.13 
~2. 17 


2.13 
2.50 
6.52 


4.26 
12.50 
15.22 


2.13 


2.13 


4.26 


206 




209 


56.52 


50 


13.04 


21.74 




2.17 


2 17 






Per cent for breed. 


60.15 


51.87 


41.35 


24.80 28.57 


31.5112.77 


14.29 


14.29 


1.50 


3.67 


10.52 


. 75 


1.50 2.26 


300 . 


46.15 
58.33 
68 


57. 69 K7- P.9 


42.32 34.61 


19.2311.53 
37.50 4.17 
39 12 


3.85 
12. 50 

8 


19. 23 - - - 


3.85 


3.S5 








300 

301 


58.34 
5fi 


33.33 
44 

43.24 
33.34 


37.50 
20 

32.44 
16.66 


29.17 
36 


25 
16 

18.92 
8.33 





4.17 
8 

2.70 
8.33 











301 


62.16 59.46 
75 66. 68 


29.73 32.44 2. 70i 8.11 


2.70 
8.33 




2.70 


2,70 


302 


16. 66 50 


8.34 8.33 













Per cent for breed. 


60. 49^9. 68 


43. 55 


31.46|30.65 32.26 


7.126: 8.07 


18.55! .81! .81 


4.S4 


.SI .81 


400. . 


65. 70 60 
72. 41 58- 62 


40 
37.93 


31.44 28.57 
94.14:34.48 


40 

34.48 

35.72 


2. S6| 8.57 

3.45 6.90 

21.43 


14.29-. - 2.8fi 


5.71 
3.45 






402. . 


24. 14 

42. So 










403. . 


50 


21.43 


21.43|50 57.14 




















Percent for breed. 


65.39 


51.29 


34.6132.0537.18 


37.18 


2.5610.26 


24. 36 


1.28 


3. So 








Total per cent 


59.53 


53.48 


39.76 


30.93 30.23 


32.09 


8. 60;13. 25 


19.30| .70 


2.32 


7.90 .23 


.70 


.93 



SPECIFIC GRAVITY OF MILK SOLIDS. 



11 



Table 3. — Average specific gravity, nitrogen, sugar, fat, and total solids for each cow, 

each breed, and the total average. 



Cow No. 


Specific 

gravity 
ofmilk. 


Total 
nitro- 
gen. 


Sugar. 


Fat. 


Solids 
not fat. 


Total 
solids — 

gravi- 
metric. 


Total 
solids — 
Bab- 
cock. 


Total 
solids- 
Rich- 
mond. 


Total 
solids — 
Fleisch- 
mann. 


4... 
99.. 
118. 


Average for breed 


Degrees. 
33.4 
32.9 
34.2 


P. ct. 

0.61 

.53 

.65 


P. ct. 
4.79 
4.99 
4.87 


P.ct. 

4.88 
4.70 
5.39 


P.ct. 
9.23 
8.95 
9.66 


P.ct. 
14.19 
13. 65 
15.05 


P.ct. 
14.21 
13.87 
15.02 


P.ct. 
14.35 
14.02 
15.16 


P.ct. 

14.47 
14.13 
15.28 




33.5 


.60 


4.88 


4.99 


9.28 


14.30 


14.37 


14.51 


14.63 


205. 


32.9 
29.8 
31.4 


.47 
.44 
.52 


5.09. 
4.25 
4.29 


3.23 
2.96 
3.09 


8.78 
7. 98 
8.45 


11.99 
10.94 
11.51 


12.10 

11 

11.54 


12.24 
11.16 
11.70 


12. 37 


206 


11.26 


209 -- 


11.80 




Average for breed 






31.4 


.48 


4.54 


3.09 


8.40 


11.48 


11.55 


11.70 


11.81 


300. 


33.3 
31.8 
33.1 
32.6 
31.7 


.60 
.48 
.54 
.51 
.55 


4.86 

4.84 

5.02 

5 

4.78 


4.20 
3.49 
4.28 
3.84 
4.49 


9.23 

8.56 
9.11 

8.85 
8.77 


13.43 
12. 05 
13.39 
12.72 
13.24 


13. 38 
12.12 
13.41 
12.77 
13.32 


13.52 

12.28 
13.54 
12. 93 
13.48 


13. 64 


300. 




12. 39 


301 


13.67 


301 


13.04 


302 


13.58 




Average for breed 






32.5 


.54 


4.90 


4.06 


8.90 


12.96 


13 


13.15 


13.26 


400. 


33.9 
33.8 
33.2 


.53 

.54 
.49 


5.09 

4.97 
5.23 


3.86 
4.04 
3.34 


9.22 
9.16 
8.79 


13.08 
13. 20 
12.12 


13.12 
13. 28 
12.31 


13.24 
13.41 
12.49 


13.38 


402 


13.55 


403.. 


12.50 




Average for breed 

Total average 






33.6 


.52 


5.10 


3.75 


9.06 


12.80 


12.90 


13. 05 


13.14 




32.8 


.54 


4.86 


3.97 


8.91 


12.89 


12.96 


13.10 


13.21 









THE SPECIFIC GRAVITY OF MILK SOLIDS. 

Assuming that milk is a mixture of milk plasma and fat, it will be 
seen at once that if the specific gravities of the fat and of the plasma 
solids were constant quantities the relation of the specific gravity of 
the milk, the percentage of fat, and the percentage of plasma solids 
could be expressed mathematically. From such a mathematical 
relation it would be but a step to derive a formula for finding any one 
of these factors when the other two were given. 

The specific gravity of butter fat is about 0.93 at 15° C, the varia- 
tion from this figure in different samples being so slight as to be 
negligible for all practical purposes. It may then be considered as a 
constant, and is so treated in the formulas compared in the previous 
part of this bulletin. 

The specific gravity of the plasma solids is not a constant, but 
varies in different samples of milk. This variation is, however, not 
a large one, being generally within comparatively narrow limits in 
normal milk. It is because of these narrow limits that formulas are 
admissible. 

Richmond/ working in England, found from the analyses of over 
200 samples of milk the average specific gravity of the plasma solids 
to be 1.616. Fleischmann 2 obtained the figure 1.6007 from the aver- 
age of a large number of samples from cows in North Germany. The 

i Richmond's Dairy Chemistry, p. 6. London, 1899. 
2 Fleischmann's Book of the Dairy, p. 33. London, 1896. 



12 ESTIMATION OF TOTAL SOLIDS IN MILK. 

latter investigator has published a formula for calculating the specific 
gravity of the plasma solids when the specific gravity of the milk, the 
percentage of fat, and the percentage of total solids are known, thus: 

sXo(t-f) 

n ~ lOOXo- sxo (100 -t)-sf 

The values for the specific gravity of plasma solids, the specific 
gravity of milk, the percentage of total solids, the percentage of fat, 
and the specific gravity of the fat in this formula are denoted, 
respectively, by the letters n, s, t,f, and o. 

Applying this formula to the average of the 430 determinations 
given in Tables 1, 2, and 3 it is found that 1.638 is the average 
specific gravity of the plasma solids. 

It has already been noted that the Fleischmann formula gave 
figures higher than the Richmond, which in turn gave figures higher 
than the Babcock. Since the average of the total solids determined 
by the latter agreed very closely with our gravimetric ally determined 
total solids, it may be inferred that if Babcock had given a figure for 
the specific gravity of plasma solids to correspond with his revised 
formula, it would have been very close to our figure. It may be 
seen that the difference between these three formulas is largely due 
to the difference in the specific gravity of the plasma solids of the 
milk chosen by the respective investigators to represent the normal. 

As previously noted, Babcock's original formula appeared in 1891 
and its corrected form in 1895. As it originally stood it was: 

Plasma S olids^( 10 ; _ f-g g/ -l)x(100-/)2.6 

In the above, S represents the specific gravity and/ the percentage 
of fat. Subsequent to its publication Babcock found the constant, 
2.6, too high and changed it to 2.5, so that the formula as it now 
stands is: 

Plasma solids -(j™*^- l)x (100 -/) 2.5 

This revised form is the one used in the former part of this bulletin. 1 
In deriving this formula Babcock assumes that the difference 
between the specific gravity of water and that of milk plasma is 
nearly in direct proportion to the solids which the plasma contains, 2 
and that if this difference be divided by a constant factor which 

1 With the exception of the introduction of a few intermediate steps and the substitution of the term 
plasma for serum, the subject-matter showing the derivation of the Babcock formula was taken almost 
verbatim from his original article, to which reference has already been made. When the revised formula 
was published no figures for the values of x and a were given. Rather than use his original figures, which 
are now obsolete, it was thought advisable to use our own figures for the purposes of illustration; hence 
the factor 2.47 will be found in the resulting formula instead of 2.5. 

* Dr. Babcock calls attention to the fact that this assumption is not quite correct (see Twelfth Annual 
Report, Wisconsin Agricultural Experiment Station, p. 121), since if the plasma solids were always of the 
same composition the specific gravity of the plasma solids and the plasma would change at different rates. 
This error, he states, is a very small one and is counterbalanced by the variation in the composition of the 
plasma solids in normal milk. 



SPECIFIC GRAVITY OF MILK SOLIDS. 13 

represents the increase in specific gravity caused by 1 per cent of 
plasma solids the result will be the percentage of solids in the plasma. 
If the percentage of solids in the plasma found in this way be multi- 
plied by the percentage of plasma in the milk and the product divided 
by 100, the result will be the percentage of plasma solids in the milk 

Let 

/= percentage of fat in any milk. 

100— /= percentage of plasma in any milk. 
S = specific gravity of milk at 60° F. 
0.93 = specific gravity of butterfat at 60° F. 
# = specific gravity of plasma at 60° F. 
a = increase in the specific gravity of the plasma caused 
bv 1 per cent of plasma solids. 
Then, I.— 

Percentage of plasma solids in any milk = X — inn 

—a- = volume in c. c. of 100 grams of milk. 

= volume in c. c. of plasma in 100 grams milk. 

f 

^r— or 1.0753/= volume in c. c. of fat in 100 grams milk. 

Since the volume of the milk equals the sum of the volumes of fat 
and plasma, then 

^o = io£-/ +10753/ 

Clearing of fractions and reducing 

100x=100S-Sf+1.075SSfx 

Transposing and combining 

z(100 - 1.0753S/) = lOOSf-Sf 

n - _ lOOS-Sf 
X 100-1.0753/S/ 

II. By first getting a value for x from a large number of analyses a 
is found. Subtract 1 from x and divide the remainder by the per- 
centage of solids which the plasma contains. The percentage of 
solids in the plasma is found by dividing the percentage of plasma 
solids in the milk by the percentage of plasma (100—/) and multi- 
plying by 100. 

The value of a in our work is 0.004044. 

Substituting the value of x and a in I. 

1008 -Sf 
100-1.07535/ 100-/ 

.004044 X 100 



( 100-1 075SSY ~ 1 ) X ^ 10 ° — f^ X 2-4703 = percentage of plasma 



14 



ESTIMATION OF TOTAL SOLIDS IN MILK. 



The percentage of total solids is found by adding the percentage of 
fat to the percentage of plasma solids. 

It will readily be seen that Babcock's value of representing the 
increase in specific gravity of the plasma caused by 1 per cent of the 
plasma solids depends directly upon the specific gravity of the plasma 
solids. This is a common point of weakness in all formulas derived 
for the same purpose. 

Since the plasma solids are composed of several solids, chief of 
which are milk sugar, proteins, and ash, the specific gravity of the 
plasma solids must depend upon the specific gravity of the various 
components taken individually. Richmond 1 states that the specific 
gravity of milk sugar is 1.666, that of the proteins 1.346, and that of 
the ash 4.12. A change in the ratio of the milk sugar and the pro- 
teins will afiect the specific gravity of the plasma solids and conse- 
quently the value of a. With a milk containing an abnormally high 
percentage of sugar the total solids calculated by the formulas would 
be theoretically too high. They would be too low under the reverse 
condition. 

This is very well shown in the table below, the results in which are 
obtained from milk of a cow of the Shorthorn breed at the parturition 
period. As is well known, the milk taken at this time is abnormally 
high in proteins, while the milk sugar is abnormally low. The cow 
freshened on the morning of October 23. 

Table 4. — Showing application of the Babcock formula to colostrum milk. 





Total 
nitrogen. 


Fat. 


Sugar. 


Total solids. 


Date. 


Gravi- 
metric. 


Babcock 
formula. 


Oct. 23— a. m 


Per cent. 

2.26 

1.24 

1.09 

.98 

.93 

.87 

.82 

.79 

.73 


Per cent. 
1.30 
3.26 
4.57 
5.42 
5.08 
6.23 
5.35 
5.87 
5.60 


Per cent. 
2.65 
3.81 
4.41 
4.89 
4.63 
4.79 
5.40 
5.53 
4.96 


Per cent. 
22.22 
15.78 
16.53 
17.19 
16.34 
17.04 
16.06 
16.85 
15.26 


Per cent. 
12.86 


Oct. 24 — a. m 


12.55 


Oct. 24 — p. m 


14.06 


Oct. 25 — a. m 


15.04 


Oct. 25 — p. m 


14. 67 


Oct. 26— a. m 

Oct. 26— p. m 


16.01 
14.88 


Oct. 27 — a. m 


15. 53 


Oct. 27— p. m 


15.18 







Table 5 was prepared from averages given in Table 3. The specific 
gravity of the plasma and the increase in specific gravity of the 
plasma caused by 1 per cent of plasma solids (Babcock's value a) 
were calculated by means of the Babcock formula. The specific 
gravity of the plasma solids was calculated by the formula of Fleisch- 
mann, to which reference has already been made. The last column 
of figures shows the factor which would result in each case were our 
figures for the value of a substituted for Babcock's in his formula. 

1 Richmond's Dairy Chemistry, p. 65. 



ACCURACY OF LACTOMETERS. 
Table 5. — Average data for each breed of cows. 



15 



Breed. 



Num- 
ber of 
anal- 
yses. 



Average 
specific 
gravity 
of milk. 



Average 

fat 
content. 



Average 

total 

solids. 



Average 

specific 

gravity 

of plasma. 



Average 
specific 
gravity 
of plasma 
solids. 



Average 
value 
for a. 



Factor. 



Jersey 

Holstein . . 
Ayrshire . . 
Shorthorn 
All breeds 



95 
133 
124 

78 
430 



1.0335 
1.0314 
1.0325 
1.0336 
1.0328 



Per cent. 
4.99 
3.09 
4.06 
3.75 
3.97 



Per cent. 
14.30 
11.48 
12.97 
12.80 
12.89 



1.03958 
1.03500 
1.03734 
1.03811 
1.03752 



1.648 
1.624 
1.637 
1.650 
1.638 



0. 004052 
. 004038 
. 004025 
. 004049 
. 004044 



2.468 
2.477 
2.485 
2.469 
2.470 



It will be noted that there is no great variation in the figures in 
the last three columns, and also that the factor is but slightly different 
from Babcock's 2.5. This would, of course, follow from the close 
agreement between the grand average figures for the gravimetric 
total solids and that calculated by the Babcock formula. 

EXPERIMENTS TO DETERMINE ACCURACY OF LACTOMETERS. 

Having found which formula was best adapted for the purpose, 
the next question which naturally suggests itself is whether the ordi- 
nary lactometer when used to determine the specific gravity of milk 
is sufficiently accurate. , 

Thirteen lactometers were available for comparison; 11 of these 
were Quevenne lactometers and 2 were of the type known as the New 
York Board of Health lactometer. These were thought to represent 
fairly well the ordinary lactometers on the market. They were com- 
pared with the Westphal balance on three different samples of milk, 
with the following results: 

Table 6. — Showing comparisons of various lactometers ivith Westphal balance. 





Specific gravity of milk 
samples. 


Instrument. 


Specific gravity of milk 
samples. 


Instrument. 


Skim 
milk. 


Hol- 
stein. 


Hol- 
stein 
fresh. 


Skim 
milk. 


Hol- 
stein. 


Hol- 
stein 
fresh. 


Quevenne lactometer 1 . . . 
Quevenne lactometer 2 . . . 
Quevenne lactometer 3 . . . 
Quevenne lactometer 4. . . 
Quevenne lactometer 5. . . 
Quevenne lactometer 6. . . 
Quevenne lactometer 1 ... 
Quevenne lactometer 8 . . . 


1.0345 
1.0340 
1.0340 
1.0335 
1.0330 
1.0340 
1. 0360 
1.0370 


1. 0315 
1.0310 
1.0315 
1.0300 
1.0300 
1.0310 
1.0330 
1.0335 


1. 0325 
1.0320 
1. 0325 
1.0320 
1.0315 
1.0325 
.1.0340 
1. 0350 


Quevenne lactometer 9 . . . 
Quevenne lactometer 10. . 
Quevenne lactometer 11 . . 
New York Board of 

Health lactometer 1 

New York Board of 

Health lactometer 2 

Westphal balance 


1.0350 
1.0335 
1.0350 

1.0328 

1.0299 
1.0345 


1.0320 
1.0310 
1.0320 

1.0307 

1.0281 
1.0313 


1.0330 
1.0318 
1.0330 

1.0319 

1.0290 
1.0325 



A glance at the foregoing figures will show discrepancies which 
are sufficient in some cases to account for as much as 1 per cent of 
total solids calculated from the Babcock formula. Of course, much 
of the discrepancy is due to the fault of the manufacturer in not 



16 



ESTIMATION OF TOTAL SOLIDS IN MILK. 



properly calibrating the instruments. However, in none of the 
lactometers tested was the scale divided into less than whole Quevenne 
degrees. Fractions of degrees could be read only by interpolation, 
and then the divisions were generally so narrow that a closer inter- 
polation than one-half of a degree was impossible; in fact, in some 
cases it was hardly possible to read closer than 
whole degrees. One Quevenne degree with a Bab- 
cock formula will account for 0.25 per cent of total 
solids. It is therefore obvious that the ordinary 
lactometer is unsuited for other than very gross 
results. 

The sensitiveness of the hydrometer, or lactom- 
eter, as it is termed when made for the special pur- 
pose of determining the specific gravity of milk, 
depends upon the ratio of the size of the bulb to the 
diameter of the stem. The larger the bulb is in pro- 
portion to the diameter of the stem, the more sensi- 
tive will be the lactometer, or, in other words, the 
longer will be the spaces representing units on the 
scale. A lactometer, then, may be made more sen- 
sitive by either diminishing the size of the stem or 
by enlarging the bulb. But the smaller the stem 
the more fragile is the instrument, and the larger 
the bulb, the more cumbersome. 

In designing a lactometer for our work several 
points were taken into account: (1) That it should 
accommodate the usual ranges of normal milk; 
(2) that it should have scale divisions representing 
tenths of Quevenne degrees; and (3) that it must 
be neither too fragile nor too cumbersome for prac- 
tical use outside of a chemical laboratory. 

After considerable experimenting in the labora- 
tory the dimensions of an instrument were decided 
upon and several were made to order from our 
specifications. (See fig. 1.) 

In order to test these lactometers against the 
Westphal balance, salt solutions were used, and the 
following results were obtained: 




Fig. 1. — Lactometer 
designed for use in 
experimental work. 



Table 7. — Comparison of new lactometers with Westphal balance, using salt solutions. 



Solution. 


West- 
phal. 


Lactom- 
eter I. 


Lactom- 
eter II. 


I 


1.0245 
1.0283 
1.0315 
1. 0352 


1.0248 
1.0287 
1.0318 
1.0351 


1.0248 


II 


1.0287 


Ill 


1.0319 


IV : 


1.0352 







TESTS OF BABCOCK FORMULA AND NEW LACTOMETER. 



17 



Little comment is required on the above figures, as it is seen that 
the results obtained with the lactometers are practically identical 
with those of the Westphal balance. 

TESTS OF BABCOCK FORMULA AND NEW LACTOMETER WITH 

INDIVIDUAL MILKINGS. 

Since the figures given in the first part of this bulletin were all 
based on results obtained on composite samples from individual cows, 
it was deemed desirable at this point to test the Babcock formula 
on milk from individual milkings and at the same time to compare 
the figures obtained by the new lactometers and the Westphal bal- 
ance on the same milk. The only change in the laboratory procedure 
was that the percentage of fat was obtained by the Babcock test 
instead of by the extraction method. 

Four cows were selected with which to make the tests under con- 
ditions comparable with those found in making official tests of dairy 
cattle. For this purpose pure-bred cows were used, representing four 
breeds. These cows were milked and fed three times daily — at 
5 a. m., 1 p. m., and 8 p. m. The animals remained in the barn the 
greater part of the time. They were allowed the freedom of a lot 
from two to four hours in the forenoon and from one to two hours 
in the afternoon. Each animal was fed according to her individual 
capacity and characteristics. The cows were on official test at the 
time these samples were secured and were receiving such treatment 
as, in the judgment of the herdsman, would give the best results 
for this purpose. The rations consisted of corn, silage, alfalfa hay, 
corn meal, bran, oats, and oil meal in somewhat varying proportions. 
Table 8 gives more specific data regarding the four cows used. The 
duration of the test was seven days, the average yields of milk and 
of butter fat for this period being as follows : 

Table 8. — Milking records of cows used in tests. 



No. of 
Cow. 



16. 
204 
300 
401 



Breed. 



Jersey 

Holstein . . 
Ayrshire . 
Shorthorn 



Days 
in 

milk. 



367 

119 

20 

258 



Average 

yield of 

milk per 

day. 



Pounds. 
10.9 
16.7 
13.7 
10.5 



Average 
yield of 
fat per 



Pounds. 

0.57 

.57 

.53 

.43 



18 



ESTIMATION OF TOTAL SOLIDS IN MILK. 



The results of the work on the individual milkings from the cows 
described in the above table are found in Tables 9, 10, 11, and 12, 
next following. 

Table 9. — Lactometer results on individual milkings from Holstein-Friesian cow No. 204- 





Specific gravity— 


Fat. 


Percentage of total solids- 


Sample No. 


Westphal 
balance. 


Lactom- 
eter I. 


Lactom- 
eter II. 


Gravi- 
metric. 


West- 
phal. 


Lactom- 
eter I. 


Lactom- 
eter II. 


Ll 


1.0310 
1. 0320 
1.0315 
1.0308 
1.0317 
1.0316 
1.0336 
1.0321 
1.0299 
1.0320 
1.0341 
1.0318 
1.0318 
1. 0327 
1.0303 
1.0304 
1.0327 
1.0312 
1.0313 
1.0313 
1.0310 


1.0321 
1.0326 
1.0315 
1.0312 
1.0319 
1.0320 
1.0335 

1. 0323 
1.0300 
1.0325 
1.0337 
1. 0316 
1.0320 
1.0322 
1.0298 
1. 0312 

1. 0324 
1.0312 

1. 0320 

1. 0321 
1.0317 


1.0320 
1.0324 
1.0312 
1.0310 
1.0317 
1.0318 
1.0336 
1.0324 
1.0301 
1.0322 
1.0335 
1. 0314 
1.0320 
1.0322 
1.0298 
1.0308 
1.0322 
1.0309 
1.0317 
1.0319 
1.0317 


Per cent. 
2.9 
3.2 
4.3 
3.5 
2.9 
3.8 
3.4 
3.3 
3.5 
3.5 
2.93 
4 

3.3 
2.75 
4.2 
4.23 
2.8 
3.95 
3.70 
3.35 
3.78 


Per cent. 
11.59 
12.26 
12.93 
11.91 
11.57 
12.72 
12.70 
12.23 
12.32 
12.26 
11.95 
12.62 
12.07 
11. 39 
12.84 
13.17 
11.59 
12.60 
12.61 
12.07 
12,44 


Per cent. 
11.23 
11.85 
13.05 
11.91 
11.41 
12.47 
12.49 
12 

11.69 
12.21 
12.08 
12.76 
11.92 
11.49 
12.63 
12.71 
11.55 
12.55 
12.28 
11.86 
12.32 


Per cent. 
11.52 
12 

13.05 
12.01 
11.46 
12.57 
12.47 
12.05 
11.71 
12.34 
11.98 
12.71 
11.97 
11.36 
12.50 
12.91 
11.47 
12.55 
12.45 
12.08 
12.50 


Per cent. 
11.49 


L2 


11.95 


L3 


12.97 


Ll 


11.96 


L5 


11.41 


L6...... 


12.52 


L7 


12.49 


L8 

L9 

L10 

Lll 


12.07 
11.74 
12.26 
11. 93 


L12 


12.66 


L13 


11.97 


L14 


11.36 


L15 


' 12.50 


L16 


12.81 


L17 


11.42 


L18 


12. 48 


L19 


12.38 


L20 


12.01 


L21 


12.50 







Table 10. — Lactometer results on individual milkings from Jersey cow No. 16. 





Specific gravity — 


Fat. 


Percentage of total solids- 


Sample No. 


West- 
phal 
balance. 


Lactom- 
eter I. 


Lactom- 
eter II. 


Gravi- 
metric. 


West- 
phal. 


Lactom- 
eter I. 


Lactom- 
eter II. 


L22 


1.0325 
1. 0346 
1. 0325 
1.0342 
1. 0346 
1.0333 
1.0340 
1.0332 
1.0327 
1. 0345 
1. 0355 
1. 0344 
1.0340 
1.0350 
1.0330 
1.0351 
1. 0343 
1.0332 
1.0351 
1.0354 
1.0333 


1.0329 
1.0348 
1.0330 
1.0347 
] . 0350 
1.0335 
1. 0351 
1. 0338 
1. 0333 
1.0348 
1.0357 
1.0348 
1.0342 
1.0350 
1.0333 
1.0354 
1.0347 
1. 0333 
1. 0345 
1. 0347 
1. 0333 


1. 0327 
1. 0348 
1. 0329 
1.0347 
1.0348 
1.0333 
1.0349 
1. 0336 
1 . 0333 
1.0349 
1.0355 
1.0346 
1. 0341 
1.0348 
1.0330 
1.0354 
1.0346 
1.0335 
1.0344 
1.0346 
1.0333 


Per cent. 
5.2 
5.1 
5.6 
4.88 
4.6 
5.18 
5.25 
5.20 
5.68 
5.40 
5 
5 

5.23 
4.93 
5.75 
5.15, 
5.25 
5.55 
5.20 
5.25 
5.30 


Per cent. 
14.92 
14.97 
15.45 
14.65 
14.38 
14.89 
15.25 
14.56 
15.33 
15.28 
14.85 
14.87 
14.86 
14.62 
15.50 
14.93 
J5.09 
15.20 
15.19 
15.26 
15.59 


Per cent. 
14.39 
14.79 
14.88 
14.45 
14.19 
14.59 
14.82 
14.56 
15.05 
15.14 
14.91 
14.62 
14.82 
14.72 
15.18 
14.99 
14.90 
14.99 
15.05 
15.18 
14.71 


Per cent. 
14.49 
14.84 
15 

14.58 
14.30 
14.64 
15.11 
14.71 
15.20 
15.21 
14.96 
14.72 
14.87 
14.72 
15.26 
15.06 
15 

15.02 
14.89 
15 
14.71 


Per cent. 
14.44 


L23 


14.84 


L24 


14.98 


L25 


14.58 


L26...'. 


14.24 


L27 


14.59 


L28 


15.05 


L29 


14.66 


L30 

L31 

L32 

L33 


15.20 
15. 24 
14.91 
14.67 


L34 

L35 

L36 


14.85 
14.66 
15.18 


L37 


15.06 


L38 


14.97 


L39 


15.07 


L40 


14.86 


L41 


14.97 


L42... .... 


14.71 







EFFECT OF TEMPERATURE ON SPECIFIC GEAVITY. 19 

Table 11. — Lactometer results on individual milkings from Shorthorn cow No. 401. 





Specific gravity — 


Fat. 


Percentage of total solids — 


Sample No. 


West- 

phal 

balance. 


Lactom- 
eter I. 


Lactom- 
eter II. 


Gravi- 
metric. 


West- 
phal. 


Lactom- 
eter I. 


Lactom- 
eter II. 


L43 


1.0340 
1.0344 
1.0340 
1.0350 
1.0352 
1.0340 
1.0344 
1.0357 
1.0335 
1.0308 
1.0355 
1.0344 
1.0347 
1.0349 
1.0337 
1.0335 
] . 0350 
1.0362 
1.0355 
1.0358 
1.0344 


1.0342 
1.0345 
1.0342 
1.0352 
1.0354 
1.0343 
1.0348 
1.0363 
1.0337 
1.0316 
1.0360 
1.0351 
1.0348 
1.0352 
1.0339 
1.0339 
1.0355 
1.0360 
1.0359 
1.0363 
1.0351 


1.0342 
1.0344 
1.0342 
1.0351 
1.0353 
1.0342 
1.0347 
1.0363 
1.0336 
1.0317 
1.0380 
1.0349 
1.0345 
1.0350 
1.0338 
1.0338 
1.0354 
1.0359 
1.0360 
1.0364 
1.0349 


Per cent. 
3.8 
3.65 
4.5 
3.9 
3 

4.4 
4 

3.7 
4.8 
3.55 
2.95 
4.45 
4.50 
4.45 
5 

4.65 
3.60 
4.60 
4.40 
4.15 
4.30 


Per cent. 
13.44 
13.22 
14.43 
13.80 
12.76 
14.29 
13.54 
13.82 
14.31 
11.92 
12.67 
13. 59 
14.14 
13.92 
14.48 
14.23 
12.73 
14.56 
14.37 
14.04 
14. 


Per cent. 
13.08 
13 

13.92 
13.45 
12.41 
13.80 
13.42 
13.39 
14.16 
11.97 
12.43 
13.96 
14.10 
14.09 
14.40 
13.98 
13.09 
14.60 
14. 19 
13.96 
13.78 


Per cent. 
13.13 
13.03 
13.97 
13.50 
12.46 
13.88 
13.52 
13.54 
14.21 
12.17 
12.55 
14.15 
14.12 
14.17 
14.49 
14.07 
13.22 
14.55 
14. 28 
14.09 
13.97 


Per cent. 
13.13 


L44 


13 


L45 


13.97 


L46 


13.48 


L47 


12.44 


L48 


13.85 


L49 


13.50 


L50 


13.54 


L51 

L52 


14.18 
12.20 


L53 


12.55 


L54 


14.09 


L55 

L56 


14.05 
14. 12 


L57 


14.47 


L58 


14.05 


L59 


13.19 


L60 

L61 


14.52 
14.31 


L62 

L63 


14.11 
13.91 







Table 12. — Lactometer results on individual milkings from Ayrshire cow No. 300. 





Specific gravity — 


Fat. 


Percentage of total solids — 


Sample No. 


West- 

pnal 

balance. 


Lactom- 
eter I. 


Lactom- 
eter II. 


Gravi- 
metric. 


West- 
phal. 


Lactom- 
eter I. 


Lactom- 
eter II. 


L64 


1.0320 
1.0300 
1.0322 
1.0325 
1.0326 
1.0304 
1.0315 
1.0317 
1.0313 
1. 0295 
1.0308 
1. 0320 
1.0315 
1.0327 
1.0320 
1.0322 
1.0326 
1.0295 
1.0330 
1.0296 
1.0278 


1.0327 
1.0303 
1.0323 
1.0327 
1. 0331 
1.0310 
1.0315 
1.0323 
1.0309 
1.0294 
1.0310 
1.0322 
1.0317 
1.0327 
1.0322 
1.0324 
1.0329 
1.0290 
1.0328 
1.0298 
1.0280 


1.0325 
1.0301 
1.0321 
1.0327 
1. 0328 
1.0308 
1.0313 
1.0322 
1.0305 
1.0294 
1.0308 
1.0319 
1.0316 
1.0327 
1.0320 
1.0322 
1.0326 
1.0287 
1.0328 
1.0297 
1.0278 


Per cent. 
3 

5.10 
2.50 
4.05 
2.65 
4.25 
2.75 
3.10 
3.15 
5 

3.25 
4.25 
4.90 
3.80 
4. 90 
4.50 
3.75 
4.75 
3.30 
4.25 
5.40 


Per cent. 
11.52 
13.38 
10.79 
12.99 
11.21 
12.40 
11.01 
11.72 
11.45 
13.42 
11.53 
13.41 
13.61 
12.49 
13. 67 
13. 54 
12.06 
12.48 
12. 
12.51 
13.15 


Per cent. 
11.61 
13.63 
11.05 
13 

11.33 
12.71 
11.18 
11.66 
11.62 
13.39 
11.61 
13.12 
13.77 
12.75 
13.90 
13.47 
12.66 
13.09 
12.22 
12.51 
13.44 


Per cent. 
11.79 
13.71 
11.08 
13.06 
11.47 
12.86 
11.18 
11.81 
11.51 
13.36 
11.66 
13.17 
13.82 
12.75 
13.95 
13.52 
12.74 
12. 96 
12.17 
12.56 
13.49 


Per cent. 
11.74 


L65 


13.66 


L66 


11.03 


L67 


13.06 


L68 


11.38 


L69 


12.75 


L70 


11.13 


L71 


11.78 


L72 


11'. 42 


L73 


13.36 


L74 


11.61 


L75 


13.09 


L76 


13.79 


L77 


12.75 


L78 


13.90 


L79 


13.47 


L80 


12.66 


L81 


12.89 


L82 


12.17 


L83 


12.54 


L84 


13.44 







EFFECT OF TEMPERATURE ON SPECIFIC GRAVITY OF MILK. 

An increase in temperature is accompanied by a lowering of the 
specific gravity as determined by the lactometer. To show the 
importance of maintaining the proper temperature when using the 
lactometer and at the same time to determine the size of the error 
introduced by the difference of a few degrees in temperature, specific 
gravity determinations were made at different temperatures on 



20 



ESTIMATION OF TOTAL SOLIDS IN MILK. 



several samples of milk. Only ordinary precautions were taken in 
this experiment, and the results are about such as would be obtained 
were the lactometers in practical use. 

Samples of milk were taken from representatives of the four breeds 
of cows previously used. 

Table 13. — Effect of temperature on specific gravity of milk when determined with new 

lactometer. 



Temperatures. 


Jersey milk. 


Shorthorn milk. 


Ayrshire milk. 


Holstein-Friesian 
milk. 


Specific 
gravity. 


Differ- 
ence. 


Specific 
gravity. 


Differ- 
ence. 


Specific 
gravity. 


Differ- 
ence. 


Specific 
gravity. 


Differ- 
ence. 


9°C 


1. 0364 
1.0360 
1. 0356 
1. 0351 
1. 0345 
1. 0338 
1. 0331 




1. 0365 
1. 0361 
1. 0357 
1. 0352 
1. 0347 
1. 0341 
1. 0335 




1. 0330 
1. 0327 
1. 0323 
1. 0318 
1. 0313 
1. 0308 
1. 0302 




1. 0291 
1. 0287 
1. 0283 
1. 0279 
1. 0275 
1. 0270 
1. 0265 




11°C 

13°C 


0. 0004 
.0004 
.0005 
.0006 
.0007 
.0007 


0. 0004 
.0004 
.0005 
.0005 
.0006 
.0006 


0. 0003 
.0004 
.0005 
.0005 
.0005 
.0006 


0. 0004 
.0004 


15°C 


.0004 


17° C 


.0004 


19° C 


.0005 


21°C 


.0005 






Average 




. 0006 




.0005 1 


.0005 




.0004 











Table 14, — Showing composition of milk used in Table 13. 



Milk. 



Fat. 



Total 
solids. 



Jersey 

Shorthorn 

Ayrshire 

Holstein-Friesian 



Per cent. 
5.2 
4 

3.7 
2.7 



Per cent. 
15.21 
13.78 
12.28 
10.02 



It will at once be seen that the variation is different in different 
samples and also at different temperatures with the same sample. 
The greatest variation is in the Jersey, milk where the percentage 
of total solids is highest, and least in the Holstein-Friesian milk, 
where the percentage of total solids is lowest. As the temperature 
rises the variation for each degree increases. 

The average variation per centigrade degree counting all four 
breeds, is 0.00025, which would account for an error of about 0.08 
per cent total solids if calculated with the Babcock formula. Reduced 
to Fahrenheit degrees the error would be five-ninths of 0.08, or about 
0.044 per cent for each degree. 

recknagel/s phenomenon. 

Milk when freshly drawn contains numerous bubbles of gas, and 
it is not until these have disappeared that the specific gravity can 
be determined. It has been demonstrated by Recknagel x and con- 



i Milehzeitung, Band 12, p. 419, Bremen, 1883. 



USE OF MODIFIED LACTOMETER. 21 

firmed by other investigators that the specific gravity of milk changes 
on standing. On taking the specific gravity of milk after the air 
bubbles had escaped and again several hours later he found an 
increase. This peculiarity is called the Recknagel phenomenon. 
He ascribes the increase to a change in the volume of the proteins. 
The increase begins two or three hours after milking, and if the milk 
is held at about 15° C. continues with decreasing rapidity for two 
days. The amount of the increase is between 0.0008 and 0.0015, 
depending on the richness of the milk. This change is accelerated 
by lower temperatures, and the normal specific gravity, or the point 
where no further change takes place, may be obtained by keeping 
the milk at 5° C. or lower for six hours. 

HOW TO USE THE MODIFIED LACTOMETER AND TABLE. 

This section is designed to assist those who may desire to make 
use of the modified lactometer described in the preceding section 
and who are not accustomed to using delicate lactometers. 

Materials required: 1. The lactometer. 2. A pan of warm water. 
3. An accurate dairy thermometer. 4. A suitable cylinder to con- 
tain the sample while making the reading. 

The cylinder may be made of tin or copper and should have the 
following dimensions: Inside diameter, If inches; height, 13 inches. 
To prevent it from tipping over it should have a base of the same 
material about 2f inches in diameter. 

METHOD. 

Immediately after milking the milk should be thoroughly mixed 
and a sample of about 1 pint placed in a cream bottle. This should 
then be put into the refrigerator and kept there for ten or twelve 
hours, or until the next milking. It is then removed from the 
refrigerator and again well mixed by pouring back and forth several 
times from the bottle into another bottle or cup. At this point care 
must be taken not to mix air with the milk. This can be avoided 
by pouring against the sides of the receptacle to prevent foaming. 
After mixing, the bottle is placed in a pan of warm water and heated 
while being constantly stirred with the thermometer until the tem- 
perature reaches 60° F. The milk is then poured into the cylinder, 
which should also have been warmed in the pan so that it will not 
cool the milk. The lactometer is now quickly lowered into the milk, 
of which there should be a sufficient quantity in the cylinder to over- 
flow it, and allowed to come to rest. The point on the graduated 
scale which is at the same level as the surface of the milk is then 
read. This reading gives Quevenne degrees, which may be converted 
into specific gravity if desired by dividing by 1,000 and then adding 
1 to the quotient. 



22 ESTIMATION OF TOTAL SOLIDS' IN MILK. 

Owing to the tendency of the milk to form a meniscus about the 
stem of the lactometer, it is impossible to read directly the exact 
point on the scale that is at the same level as the surface of the milk. 
A safe rule for obtaining a very close approximation to the correct 
figure is to add 0.2 to the reading taken where the top of the meniscus 
strikes the scale. For example, if the scale reads 31.8 at the top of 
the meniscus, the corrected reading in Quevenne degrees would be 32 
and the specific gravity 1.032. 

Care must be taken that the temperature of the milk when the lac- 
tometer is read is exactly 60° F.; otherwise a very considerable error 
will be introduced. After using the lactometer it should be rinsed in 
clean water, wiped dry, and restored to its case. 

The percentage of fat should be determined by the Babcock test 
either on the sample used for the specific gravity determination or 
on another taken at the same time. 

Having by this procedure found the specific gravity of the milk and 
the percentage of fat, the total solids can be found by referring to 
Table 15, which is a modified form of one published by Babcock. 1 
In our table the percentage of total solids is given. If percentage 
of plasma solids is wanted, it can be found by subtracting the percent- 
age of fat from the percentage of total solids. 

DIRECTIONS FOR USING THE TABLE. 

If the specific gravity as expressed in Quevenne degrees is a whole 
number, the percentage of total solids is found at the intersection of 
the vertical column headed by this number with the horizontal column 
corresponding to the percentage of fat. 

If the specific gravity as expressed in Quevenne degrees is a whole 
number and a decimal, the percentage of total solids corresponding to 
the whole number is first found and to this is added the fraction found 
opposite the tenth under " Proportional parts." Two examples may 
suffice for illustration: (1) Fat, 3.8 per cent; specific gravity, 32. 
Under column headed 32 we find 12.57 per cent, corresponding to 3.8 
per cent fat. (2) Fat, 3.8 per cent; specific gravity, 32.5. The per- 
centage of total solids corresponding to this percentage of fat and a 
specific gravity of 32 is 12.57. Under " Proportional parts" the frac- 
tion 0.13 appears opposite 0.5. This added to 12.57 makes 12.70, 
which is the desired percentage. 

An inspection of the table shows that the percentage of total solids 

increases practically at the rate of 0.25 for each lactometer degree 

and 1.2 for each per cent of fat. This gives rise to Babcock's simpler 

formula 

Total solids = \ £+1.2/ 

(L = lactometer reading in Quevenne degrees, and /= percentage fat). 

1 Twelfth Annual Report of the Wisconsin Agricultural Experiment Station, p. 124. 



USE OF MODIFIED LACTOMETER AND TABLE. 



23 



This simple formula can be used in cases not provided for in the 
table, and the error introduced will be inconsiderable. 

Table 15. — Table for determining total solids in milk from any given specific gravity 

and percentage of fat. 




24 



ESTIMATION OF TOTAL SOLIDS IN MILK. 



Table 15. — Table for determining total solids in milk from any given specific gravity 

and percentage of fat — Continued. 



Per 

cent- 
age of 






Lactometer reading at 60° F. 


(Quevenne degrees). 




























fat. 


2(5 


27 


2S 


29 


30 


31 


32 


33 


34 


35 


36 




Pa- 


Per 


Per 


Per 


Per 


Per 


Per 


Per 


Per 


Per 


Per 




cent 


cent 


cent 


cent 


cent 


cent 


cent 


cent 


cent 


cent 


cent 




total 


total 


total 


total 


total 


total 


total 


total 


total 


total 


total 




solids. 


solids. 


solids. 


solids. 


solids. 


solids. 


solids. 


solids. 


solids. 


solids. 


solids. 


5.00 


12.51 


12.76 


13.01 


13.26 


13.51 


13.76 


14.02 


14.27 


14.52 


14.78 


15.03 


5.05 


12.57 


12.82 


13.07 


13.32 


13.57 


13.83 


14.08 


14.33 


14.58 


14.84 


15.09 


5.10 


12.63 


12.88 


13.13 


13.38 


13.63 


13.89 


14.14 


14.39 


14.64 


14.90 


15.15 


5.15 


12.69 


12.94 


13.19 


13.44 


13.69 


13.95 


14.20 


14.45 


14.70 


14.96 


15.21 


5.20 


12.75 


13.00 


13.25 


13.50 


13.75 


14.01 


14.26 


14.51 


14.76 


15.02 


15.27 


5.25 


12.81 


13.06 


13.31 


13.56 


13.81 


14.07 


14.32 


14.57 


14.82 


15.08 


15.33 


5.30 


12.87 


13.12 


13.37 


13.62 


13.87 


14.13 


14.38 


14.63 


14.88 


15.14 


15.39 


5.35 


12.93 


13.18 


13.43 


13.68 


13.93 


14.19 


14.44 


14.70 


14.95 


15.20 


15.45 


5.40 


12.99 


13.24 


13.49 


13.74 


14.00 


14.25 


14.50 


14.76 


15.01 


15.26 


15.51 


5.45 


13.05 


13.30 


13.55 


13.80 


14.06 


14.31 


14.56 


14.82 


15.07 


15.32 


15.57 


5.50 


13.11 


13.36 


13.61 


13.86 


14.12 


14.37 


14.62 


14.88 


15.13 


15.38 


15.63 


5.55 


13.17 


13.42 


13.67 


13.93 


14.18 


14.43 


14.69 


14.94 


15.19 


15.44 


15.69 


5.60 


13.23 


13.48 


13.73 


13.99 


14.24 


14.49 


14.75 


15.00 


15.25 


15.50 


15.75 


5.65 


13.29 


13.54 


13.79 


14.05 


14.30 


14.55 


14.81 


15.06 


15.31 


15.56 


15.81 


5.70 


13.35 


13.60 


13.85 


14.11 


14.36 


14.61 


14.87 


15.12 


15.37 


15.62 


15.87 


5.75 


13.41 


13.66 


13.91 


14.17 


14.42 


14.68 


14.93 


15.18 


15.43 


15.68 


15.93 


5.80 


13.47 


13.72 


13.97 


14.23 


14.48 


14.74 


14.99 


15.24 


15.49 


15.74 


15.99 


5.85 


13.53 


13.78 


14.04 


14.29 


14.54 


14.80 


15.05 


15.30 


15.55 


15.80 


16.06 


5.90 


13.59 


13.84 


14.10 


14.35 


14.60 


14.86 


15.11 


15.36 


15.61 


15.86 


16.12 


5.95 


13.65 


13.90 


14.16 


14.41 


14.66 


14.92 


15.17 


15.42 


15.67 


15.92 


16.18 


6.00 


13.71 


13.96 


14.22 


14.47 


14.72 


14.98 


15.23 


15.48 


15.73 


15.98 


16.24 


6.05 


13.77 


14.02 


14.28 


14.53 


14.78 


15.04 


15.29 


15.54 


15.79 


16.04 


16.30 


6.10 


13.83 


14.08 


14.34 


14.59 


14.84 


15.10 


15.35 


15.60 


15.85 


16.10 


16.35 


6.15 


13.89 


14.14 


14.40 


14.65 


14.90 


15.16 


15.41 


15.66 


15.91 


16.16 


16.42 


6.20 


13.95 


14.20 


14.46 


14. 71 


14.96 


15.22 


15.47 


15.72 


15.97 


16.22 


16.48 


6.25 


14.01 


14.26 


14.52 


14.77 


15.02 


15.28 


15.53 


15.78 


16.03 


16.28 


16.54 


6.30 


14.07 


14.32 


14.58 


14.83 


15.08 


15.34 


15.59 


15.84 


16.09 


16.34 


16.60 


6.35 


14.13 


14.38 


14.64 


14.90 


15.14 


15.40 


15.65 


15.90 


16.15 


16.40 


16.66 


' 6.40 


14.19 


14.44 


14.70 


14.96 


15.20 


15.46 


15.71 


15.96 


16.21 


16.46 


16.72 


6.45 


14.25 


14.50 


14.76 


15.02 


15.26 


15.52 


15.77 


16.02 


16.27 


16.52 


16.78 


6.50 


14.31 


14.56 


14.82 


15.08 


15.32 


15.58 


15.83 


16.08 


16.33 


16.58 


16.84 


6.55 


14.37 


14.62 


14.88 


15.14 


15.38 


15.64 


15.89 


16.14 


16.39 


16.64 


16.90 


6.60 


14.43 


14.68 


14.94 


15.20 


15.44 


15.70 


15.95 


16.20 


16.45 


16.70 


16.96 


6.65 


14.49 


14.74 


15.00 


15.26 


15.50 


15.76 


16.01 


16.26 


16.51 


16.76 


17.02 


6.70 


14.55 


14.80 


15.06 


15.32 


15.56 


15.82 


16.07 


16.32 


16.57 


16.82 


17.08 


6.75 


14.61 


14.86 


15.12 


15.38 


15.62 


15.88 


16.13 


16.38 


16.63 


16.88 


17.14 


6.80 


14.67 


14.92 


15.18 


15.44 


15.68 


15.94 


16.19 


16.44 


16.69 


16.94 


17.20 


6.85 


14.73 


14.98 


15.24 


15.50 


15.74 


16.00 


16.25 


16.50 


16.75 


17.00 


17.26 


6.90 


14.79 


15.04 


15.30 


15.56 


15.80 


16.06 


16.31 


16.56 


16.81 


17.06 


17.32 


6.95 


14.85 


15.10 


15.36 


15.62 


15. 86 


16.12 


16.37 


16.62 


16.87 


17.12 


17.38 



PROPORTIONAL PARTS. 



Lactometer 
fraction. 


Fraction to 

be added 

to total 

solids. 


Lactometer 
fraction. 


Fraction to 

be added 

to total 

solids. 


Lactometer 
fraction. 


Fraction to 

be added 

to total 

solids. 


0.1 
.2 
.3 


0.03 
.05 

.08 


0.4 
. 5 
.6 


0.10 
.13 
.15 


0.7 
.8 
.9 


0.18 
.20 
.23 



SUMMAKY AND CONCLUSIONS. 25 

SUMMARY AND CONCLUSIONS. 

1. For purposes where exact percentages of total solids are de- 
manded the use of any formula will not fulfill the requirements. 

2. Of the formulas in general use that known as the Babcock 
(revised) formula gave results closest to those obtained gravimetri- 
cally. In 430 composite samples analyzed for total solids 256, or 
nearly 60 per cent, when calculated with this formula agreed within 
0.25 per cent of the figures obtained gravimetrically, and 389, or 
over 90 per cent, agreed within 0.50 per cent. In another test with 
84 samples of milk obtained from four individual cows under official 
testing conditions, determinations made on each milking showed that 
the total solids calculated by the formula in 53 cases, or 63 per cent 
of the total, agreed within 0.25 per cent of the gravimetrically deter- 
mined figures; and in 78 cases, or 93 per cent of the total, they 
agreed within 0.50 per cent. 

3. Neither individuality nor breed in the cows seemed to exert any 
notable influence upon the application of the formulas. 

4. The Babcock formula may be safely used with normal milk 
where only comparatively close approximations are required. It 
must be left to the decision of those in need of such figures as to 
whether or not the formula will fulfill their particular requirement. 

5. The lactometers in common use for determining specific gravity 
of milk are not sufficiently sensitive to be used in connection with 
the Babcock fat test for estimating total solids in milk by formula. 
A modification of the Quevenne lactometer was, however, devised 
which was found to yield results quite as accurate as those obtained 
with the Westphal balance and at the same time so constructed that 
it may be used successfully by those unskilled in the use of chemical 
apparatus. 



APPENDIX. 



Table 16. — Comparative determinations of total solids in milk. 



Test 


Cow 


Specific 
gravity 




Total solids. 


Fat. 










No. 


No. 


(Quevenne 
degrees). 


Gravi- 
metric. 


Babcock. 


Richmond. 


Fleisch- 
mann. 








Per cent. 


Per cent. 


Per cent. 


Per cent. 


Per cent. 


1 


4 


33.2 


5.07 


14.39 


14.38 


14.51 


14.65 


2 


4 


34.5 


4.66 


14.40 


14.22 


14.40 


14.48 


3 


4 


33.7 


5.06 


14.54 


14.50 


14.63 


14.76 


4 


4 


33.0 


4.93 


14.41 


14.17 


14.27 


14.43 


5 


4 


33.6 


4.83 


14.18 


14.20 


14.27 


14.46 


6 


4 


34.5 


4.80 


14.26 


14.39 


14.52 


14.65 


7 


4 


34.0 


5.02 


14.31 


14.52 


14.63 


14.79 


8 


4 


33.7 


4.83 


13.99 


14.22 


14.27 


14.48 


9 


4 


33.0 


5.14 


14.18 


14.42 


14.51 


14.68 


10 


4 


34.0 


5.00 


14.11 


14.50 


14.63 


14.76 


11 


4 


31.5 


4.97 


13.98 


13.84 


14.02 


14.10 


12 


4 


33.5 


4.68 


13.85 


13.99 


14.15 


14.25 


13 


4 


32.5 


4.77 


13.88 


13.85 


14.02 


14.11 


14 


4 


33.0 


4.50 


13.76 


13.65 


13.79 


13.91 


15 


4 


32.2 


4.38 


13.48 


13.31 


13.42 


13.57 


16 


4 


33.1 


4.44 


13.61 


13.60 


13.67 


13.87 


17 


4 


33.0 


4.26 


14.23 


13.36 


13.55 


13. 63 


18 


4 


33.6 


4.57 


13.96 


13.88 


14.03 


14.15 


19 


4 


33.0 


4. 65 


13.29 


13.83 


14.03 


14.09 


20 


4 


34.0 


4.85 


14.03 


14.32 


14.51 


14.58 


21 


4 


34.0 


5.15 


14.70 


14.68 


14.87 


14.94 


22 


4 


34.0 


4.82 


14.55 


14.28 


14.39 


14.55 


23 


4 


32.8 


5.39 


14.75 


14.67 


14.87 


14.93 


24 


4 


34.0 


5.68 


14.80 


15.32 


15.47 


15.58 


25 


4 


33.6 


5.61 


15.15 


15.13 


15.23 


15.40 


26 


99 


33. 3 


4.37 


13.09 


13.57 


13.79 


13.83 


27 


99 


33.4 


4.55 


13.54 


13.81 


14.03 


14.07 


28 


99 


33.0 


4.51 


13.49 


13.66 


13.79 


13.93 


29 


99 


34.0 


4.53 


13.43 


13.94 


14.03 


14.20 


30 


99 


32.6 


4.14 


12.72 


13.12 


13.18 


13.38 


31 


99 


32.3 


4.50 


13.20 


13.48 


13.66 


13.74 


32 


99 


32.7 


3.86 


12.87 


12.81 " 


12.94 


13.07 


33 


99 


32.9 


4.74 


13.50 


13.91 


14.03 


14.18 


34 


99 


32.4 


4.50 


13.04 


13.50 


13.66 


- 13.76 


35 


99 


32.0 


4.39 


12.84 


13.27 


13.42 


13. 53 


36 


99 


33.0 


4.32 


12.95 


13.43 


13.55 


13.70 


•37 


99 


32.7 


4.31 


12.88 


13.35 


13.42 


13.61 


38 


99 


31.0 


4.28 


12.99 


12.89 


13.06 


13.15 


39 


99 


31.8 


4.32 


12.87 


13.13 


13.30 


13.40 


40 


99 


32.2 


4.23 


12.84 


13.13 


13.18 


13.39 


41 


99 


30.5 


4.43 


12.90 


12.94 


13.05 


13.20 


42 


99 


31.0 


3.90 


12.42 


12.43 


12.58 


12.69 


43 


99 


31.0 


4.27 


13.04 


12.87 


.13.06 


13.14 


44 


99 


30.9 


3.93 


12.67 


12.44 


12.58 


12.70 


45 


99 


32.0 


4.30 


12.50 


13.16 


13.30 


13.42 


46 


99 


33.0 


4.42 


13.13 


13.55 


13.67 


13.82 


47 


99 


33.0 


4.07 


12.95 


13.13 


13.31 


13.40 


48 


99 


34.0 


4.37 


13.13 


13.74 


13.91 


14.01 


49 


99 


32.5 


4.80 


13.34 


13.89 


14.02 


14.15 


50 


99 


32.7 


4.70 


13. 66 


13.82 


13.90 


14.08 


51 


99 


32.0 


4.63 


13.26 


13.56 


13.66 


13.82 


52 


99 


32.4 


4.74 


13.85 


13.79 


13.90 


14.05 


53 


99 


35.5 


4.71 


14.00 


14.53 


14.64 


14.79 


54 


99 


34.5 


5.08 


14.55 


14.72 


14.88 


14.98 


55 


99 


32.5 


5.39 


14.66 


14.59 


14.74 


14.86 


56 


99 


34.0 


5.26 


14.83 


14.81 


14.99 


15.08 


57 


99 


35.0 


5.78 


15.32 


15.69 


15.84 


15.95 


58 


99 


36.0 


6.00 


15.61 


16.20 


16.32 


16.46 


59 


99 


32.3 


5.42 


14.85 


14.58 


14.74 


14.84 


60 


99 


34.6 


5.99 


15.89 


15.84 


15.96 


16.10 


61 


99 


33.5 


6.15 


16.11 


15.76 


15.95 


16.02 



26 



APPENDIX. 27 

Table 16. — Comparative determinations of total solids in milk — Continued. 













Total solids. 








Specific 












Test 


Cow 


gravity 


Fat. 


















No. 


No. 


(Quevenne 
degrees). 


Gravi- 
metric. 


Babcock. 


Richmond. 


Fleisch- 
mann. 








Per cent. 


Per cent. 


Per cent. 


Per cent. 


Per cent. 


62 


99 


34.9 


6.07 


16.24 


16.01 


16.20 


16.27 


63 


118 


30.0 


5.06 


13.93 


13.57 


13.77 


13.83 


64 


118 


31.0 


5.10 


14.19 


13.87 


14.02 


14.13 


65 


118 


29.7 


5.77 


14.12 


14.35 


14. 48 


14.61 


66 


118 


32.0 


5.58 


14.55 


14.70 


14.86 


14.96 


67 


118 


34.0 


5.80 


15.10 


15.46 


15.59 


15.72 


68 


118 


35.0 


5.60 


15.40 


15.47 


15.60 


15.73 


69 


118 


34.5 


5.69 


15.41 


15.45 


15.60 


15.72 


70 


118 


34.5 


5.76 


15.30 


15.54 


15.72 


15.80 


71 


118 


34.2 


5.44 


14.71 


15.08 


15.11 


15.34 


72 


118 


34.0 


5.86 


15.28 


15.53 


15.71 


15.80 


73 


118 


34.5 


5.87 


15.49 


15.67 


15.84 


15.93 


74 


118 


34.5 


6.10 


15.50 


15.95 


16.08 


16.20 


75 


118 


35.0 


5.95 


16.12 


15.89 


16.08 


16.15 


76 


118 


35.0 


5.28 


15.35 


15.09 


15.24 


15.35 


77 


118 


34.0 


5.86 


15.47 


15.53 


15.71 


15.80 


78 


118 


35.0 


5.37 


15.36 


15.19 


15.36 


15.46 


79 


118 


33.8 


5.41 


15. 20 . 


14.94 


15.11 


15.21 


80 


118 


34.0 


4.89 


14.55 


14. 37 


14.51 


14.63 


81 


118 


33.4 


4.99 


14.06 


A 14.34 
* 13.41 


14.51 


14.60 


82 


118 


32.0 


4.51 


13.98 


13.54 


13.68 


83 


118 


35.0 


4.83 


14.83 


14.55 


14.64 


14.81 


84 


118 


34.2 


5.00 


14.53 


14.55 


14.63 


14.81 


85 


118 


34.2 


4.61 


14.33 


14. 08 


14.15 


14. 35 


86 


118 


35.4 


5.15 


14.65 


15.03 


15.24 


15.29 


87 


118 


35.0 


4.57 


14.29 


14.23 


14.40 


14.50 


88 


118 


35.0 


5.21 


14.55 


15.00 


15.12 


15.26 


89 


118 


36.0 


4.86 


14.93 


14.83 


15.00 


15.09 


90 


118 


34.5 


5.54 


15.25 


15.27 


15.36 


15.54 


91 


118 


37.0 


5.49 


15.58 


15.84 


15.97 


16.10 


92 


118 


35.0 


5.74 


16.30 


15.64 


15.72 


15.90 


93 


118 


35.0 


5.42 


15.75 


15.25 


15.36 


15.52 


94 


118 


39.5 


5.14 


16.26 


16.04 


16.14 


16.30 


95 


118 


33.5 


6.29 


16.18 


15.92 


16.07 


16.19 


96 


205 


34.0 


3.19 


12.08 


12.33 


12.47 


12. 59 


97 


205 


34.0 


2.69 


11.32 


11.73 


11.87 


11.99 


98 


205 


34.0 


3.30 


10.95 


12.46 


12.59 


12.72 


99 


205 


34.0 


3.05 


11.88 


12.16 


12.35 


12.42 


100 


205 


32.5 


3.14 


11.80 


11.89 


11.98 


12.16 


101 


205 


33.0 


3.38 


11.59 


12.31 


12.47 


12.57 


102 


205 


31.4 


3.00 


11.03 


11.45 


11.62 


11.71 


103 


205 


32.0 


2.81 


12.00 


11.37 


11.50 


11.64 


104 


205 


34.5 


3.01 


11.67 


12.24 


12.36 


12.50 


105 


205 


33.0 


3.17 


11.66 


12.05 


12.23 


12.32 


106 


205 


31.5 


3.07 


11.46 


11.56 


11.74 


11.82 


107 


205 


32.5 


3.10 


11.95 


11.85 


11.98 


12.11 


108 


205 


33.0 


3.10 


11.64 


11.97 


12.11 


12.23 


109 


205 


33.5 


3.58 


12.45 


12.67 


12.83 


12.93 


110 


205 


31.4 


3.21 


11.76 


11.70 


11.86 


11.97 


111 


205 


32.1 


3.33 


12.20 


12.02 


12.10 


12.29 


112 


205 


31.2 


3.34 


11.95 


11.81 


11.86 


12.07 


113 


205 


32.5 


3.32 


11.96 


12.11 


12.22 


12.37 


114 


205 


34.0 


3.17 


12.34 


12.30 


12.47 


12.57 


115 


205 


33.7 


3.01 


11.66 


12.04 


12.11 


12.30 


116 


205 


32.8 


3.30 


11.70 


12.16 


12.35 


12.42 


117 


205 


33.0 


2.87 


11.77 


11.69 


11.87 


11.96 


118 


205 


32.5 


3.06 


11.96 


11.80 


11.98 


12.06 


119 


205 


33.0 


3.54 


12.19 


12.50 


12.59 


12.76 


120 


205 


32.0 


3.21 


11.76 


11.85 


11.98 


12.12 


121 


205 


32.0 


3.38 


12.13 


12.06 


12.22 


12.32 


122 


205 


34.0 


2.89 


11.83 


11.97 


12.11 


12. 23 


123 


205 


33.0 


3.26 


11.99 


12.16 


12.35 


12.43 


124 


205 


32.7 


3.19 


12.10 


12.00 


12.10 


12.27 


125 


205 


32.7 


3.38 


12.25 


12.23 


12.34 


12.50 


126 


205 


34.6 


3.15 


12.31 


12.43 


12.60 


12.69 


127 


205 


33.6 


3.17 


12.06 


12.20 


12.35 


12.47 


128 


205 


32.5 


3.28 


12.04 


12.06 


12.22 


12.33 


129 


205 


33.0 


2.94 


11.74 


11.78 


11.87 


12.04 


130 


'205 " 


32.5 


3.23 


12.01 


12.00 


12.10 


12.27 


131 


205 


32.2 


3.36 


12.10 


12.08 


12.22 


12.35 


132 


205 


31.7 


3.38 


12.15 


11.98 


12.10 


12.24 


133 


205 


32.5 


3.26 


12.20 


12.04 


12.22 


12.30 


134 


205 


33.0 


3.25 


11.90 


12.15 


12.35 


12.41 


135 


205 


33.0 


3.27 


12.27 


12.17 


12.35 


12.44 


136 


205 


33.7 


3.22 


12.42 


12.29 


12.35 


12.55 


137 


205 


32.0 


3.50 


12.19 


12.20 


12.34 


12.64 


138 


205 


33.5 


3.74 


12.71 


12.86 


12.95 


13.13 



28 ESTIMATION OF TOTAL SOLIDS IN MILK. 

Table 16. — Comparative determinations of total solids in milk — Continued. 













Total solids. 




Test 


Cow 


Specific 
gravity 












Fat. 










No. 


No. 


(Quevenne 
degrees). 




Gravi- 
metric. 


Babcock. 


Richmond. 


Fleisch- 
mann. 








Per cent. 


Per cent. 


Per cent. 


Per cent. 


Per cent. 


139 


205 


33.6 


3.20 


12.70 


12.24 


12.35 


12.50 


140 


205 


33.5 


3.63 


12.96 


12.73 


12.83 


12.99 


141 


205 


33.4 


3.40 


11.64 


12.43 


12.59 


12.84 


142 


205 


32.6 


3.82 


12.99 


12.73 


12.82 


13.00 


143 


206 


31.5 


3.48 


11.97 


12.05 


12.22 


12.31 


144 


206 


29.0 


3.17 


11.04 


11.05 


11.24 


11.32 


145 


206 


28.2 


2.58 


9.95 


10.15 


10.27 


10.41 


146 


206 


29.0 


3.06 


10. 84 


10.92 


11.12 


11.18 


147 


206 


29.2 


2.63 


10.10 


10.46 


10.52 


10.72 


148 


206 


29.0 


2.76 


10.04 


10. 56 


10.76 


10.82 


149 


206 


29.0 


2.29 


9.62 


10.00 


10.16 


10.26 


150 


206 


29.5 


2.70 


11.02 


10.62 


10.76 


10.88 


151 


206 


30.0 


2.58 


10.04 


10.60 


10.77 


10.86 


152 


206 


27.5 


2.94 


10.23 


10.40 


10.51 


10.66 


153 


206 


28.2 


2.76 


9.99 


10.36 


10.51 


10.62 


154 


206 


27.5 


2.96 


10.27 


10.43 


10.63 


10.69 


155 


206 


29.0 


2.71 


10.57 


10.50 


10.64 


10.76 


156 


206 


30.0 


3.10 


10.57 


11.22 


11.37 


11.48 


157 


206 


30.0 


2.72 


10.43 


10.76 


10.89 


11.03 


158 


206 


29.0 


2.94 


10.67 


10.78 


10.88 


11.04 


159 


206 


29.0 


2.78 


10.49 


10.59 


10.76 


10.85 


160 


206 


29.0 


3.06 


10.40 


10.92 


11.12 


11.18 


161 


206 


30.0 


3.13 


10.86 


11.26 


11.37 


11.52 


162 


206 


27.8 


3.01 


10.80 


10.56 


10.75 


10.82 


163 


206 


28.6 


3.05 


10.87 


10.81 


10.99 


11.07 


164 


206 


28.1 


3.05 


10.82 


10. 69 


10.87 


10.94 


165 


206 


29.0 


3.08 


10.83 


10.95 


11.12 


11.21 


166 


206 


29.0 


3.01 


10.92 


10.86 


11.00 


11.12 


167 


206 


29.0 


2.39 


10.44 


10.12 


10.28 


10.38 


168 


206 


29.5 


3.08 


10.63 


11.07 


11.24 


11.33 


169 


206 


29.0 


2.86 


10.71 


10.68 


10.88 


10.94 


.170 


206 


29.0 


2.82 


11.00 


10.63 


10.76 


10.90 


171 


206 


29.0 


3.23 


10.85 


11.13 


11.24 


11.39 


172 


206 


29.5 


3.09 


10.87 


11.08 


11.24 


11.34 


173 


206 


29.3 


3.13 


11.05 


11.08 


11.24 


11.34 


174 


206 


31.0 


2.70 


10.93 


10.99 


11.14 


11.25 


175 


206 


31.0 


3.06 


11.19 


11.42 


11.62 


11.69 


176 


206 


30.0 


2.93 


11.28 


11.02 


11.13 


11.28 


177 


206 


31.0 


3.35 


12.10 


11.77 


11.98 


12.03 


178 


206 


32.6 


3.03 


12.18 


11.79 


11.86 


12.05 


179 


206 


32.4 


3.03 


12.03 


11.74 


11.86 


12.00 


180 


206 


33.8 


3.39 


12.87 


12.52 


12.71 


12.78 


181 


206 


34.3 


3.44 


13.09 


12.70 


12.84 


12.97 


L82 


206 


35.3 


3.40 


13.09, 


12.91 


13.08 


13.17 


183 


209 


31.0 


3.95 


12.84 


12.49 


12.70 


12.75 


184 


209 


32.0 


3.14 


11.23 


11.77 


11.86 


12.03 


185 


209 


32.0 


2.59 


10.44 


11.11 


11.26 


LI. 37 


186 


209 


32.0 


2.80 


10.45 


11.36 


11.50 


11. 62 


187 


209 


32.0 


2.40 


10.20 


10.88 


11.02 


11.14 


188 


209 


30.0 


2.64 


10.09 


10.67 


10.77 


10. 93 


189 


209 


30.0 


2.68 


10.22 


10.72 


10.89 


10.98 


190 


209 


29.8 


2.67 


10.41 


10.65 


10.89 


10.92 


191 


209 


29.0 


2.54 


10.99 


10.30 


10.40 


10.56 


192 


209 


30.3 


2.72 


10.21 


10.84 


11.01 


11.10 


193 


209 


31.0 


2.96 


10.63 


11.30 


11.50 


11.57 


194 


209 


29.5 


2.72 


10.70 


10.64 


10.76 


10.90 


195 


209 


30.5 


3.00 


10.77 


11.23 


11.37 


11.49 


196 


209 


31.5 


3.09 


11.39 


11. 58 


11.74 


11.85 


197 


209 


28.5 


2.96 


11.04 


10.68 


10.87 


10.94 


198 


209 


28.6 


3.00 


10.81 


10.75 


10.87 


11.01 


199 


209 


29.8 


3.14 


11.18 


11.22 


11.37 


11.48 


200 


209 


29.5 


3.35 


11.21 


11.40 


11.60 


11.66 


201 


209 


31.0 


3.05 


11.41 


11.41 


11.62 


11.67 


202 


209 


30.8 


2.54 


10.81 


10.75 


10.90 


11.01 


203 


209 


31.0 


3.24 


11.46 


11.64 


11.74 


11.90 


204 


209 


30.0 


2.73 


10.93 


10.78 


10.89 


11.04 


205 


209 


29.5 


2.74 


10.62 


10.66 


10.76 


10.92 


206 


209 


30.5 


3.00 


11.20 


11.23 


11.37 


11.49 


207 


209 


30.0 


2.95 


10.97 


11.04 


11. 25 


11.30 


208 


209 


30.0 


3.08 


11.44 


11.20 


11.37 


11.46 


209 


209 


31.4 


2.72 


11.20 


11.11 


11.26 


11.38 


210 


209 


31.0 


3.15 


11.34 


11.53 


11.74 


11.79 


211 


209 


29.8 


2.95 


10.87 


10.99 


11.25 


11.25 


212 


209 


30.9 


3.08 


11.39 


11.42 


11. 62 


11.68 


213 


209 


30.7 


2.87 


11.30 


11.12 


11.25 


11.38 


214 


209 


31.5 


2.94 


11.53 


11.40 


11.50 


11.67 


215 


209 


31.5 


3.06 


11.57 


11.55 


11.74 


11.81 



APPENDIX. 29 

Table 16. — Comparative determinations of total solids in milk — Continued. 



Test 


Cow 


Specific 
gravity 




Total solids. 


Fat. 










No. 


No. 


(Quevenne 
degrees). 


Gravi- 
metric. 


Babcock. 


Richmond. 


Fleisch- 
mann. 








Per cent. 


Per cent. 


Per cent. 


Per cent. 


Per cent. 


216 


209 


31.0 


3.18 


11.59 


11.57 


11.74 


11.83 


217 


209 


31.3 


2.85 


11.62 


11.25 


11.50 


11.51 


218 


209 


31.3 


3.69 


12.49 


12.25 


12.46 


12.52 


219 


209 


32.2 


3.75 


12.68 


12.55 


12.62 


12.81 


220 


209 


33.0 


3.32 


12.61 


12.23 


12.35 


12.50 


221 


209 


33.3 


3.33 


12.53 


12.32 


12.47 


12.58 


222 


209 


32.6 


3.29 


12.28 


12.10 


12.22 


12.36 


223 


209 


33.5 


3.27 


12.76 


12.30 


12.47 


12.56 


224 


209 


35.6 


3.52 


13.20 


13.12 


13.20 


13.39 


225 


209 


36.0 


3.74 


13.70 


13.49 


13.56 


13.75 


226 


209 


34.4 


3.75 


13.70 


13.10 


13.25 


13.36 


227 


209 


37.0 


3.76 


13.98 


13.76 


13.93 


14.02 


228 


209 


34.4 


4.05 


13.56 


13.46 


13.68 


13.72 


229 


300 


33.0 


5.19 


14.53 


14.48 


14.63 


14.74 


230 


300 


33.3 


4.54 


13.76 


13.77 


13.91 


14.04 


231 


300 


33.4 


4.18 


13.76 


13.37 


13.55 


13.63 


232 


300 


33.5 


4.49 


13.94 


13.76 


13.91 


14.03 


233 


300 


33.4 


4.38 


13.93 


13.61 


13.79 


13.87 


234 


300 


33.5 


4.22 


13.51 


13. 44 


13.55 


13.70 


235 


300 


33.5 


4.46 


13.42 


13.73 


13.91 


13.99 


236 


300 


33.1 


4.07 


13.76 


13.16 


13.31 


13.42 


237 


300 


33.7 


4.23 


13.53 


13.50 


13.55 


13.76 


238 


300 


33.6 


4.22 


13.53 


13.46 


13.55 


13.73 


239 


300 


33.5 


4.05 


13.41 


13.24 


13.43 


13.50 


240 


300 


33.7 


4.01 


13.20 


13.24 


13.31 


13.50 


241 


300 


33.0 


4.16 


13.24 


13.24 


13.43 


13.51 


242 


300 


32.8 


4.08 


13.39 


13.10 


13.31 


13.36 


243 


300 


32.7 


, 4.11 


13.44 


13.11 


13.18 


13.37 


244 


300 


32.4 


3.98 


13.26 


12.88 


13.06 


13.14 


245 


300 


32.6 


3.55 


12.89 


12.41 


12.58 


12.67 


246 


300 


32.0 


4.13 


13.42 


12.96 


13.06 


13.22 


247 


300 


31.8 


4.29 


13.13 


13.10 


13.30 


13.36 


248 


300 


32.0 


4.20 


12.69 


13.04 


13.18 


13.30 


249 


300 


34.0 


4.10 


13.04 


13.42 


13.55 


13.68 


250 


300 


33.4 


4.12 


13.07 


13.29 


13.43 


13.56 


251 


300 


34 


4 02* 


13.44 


13.32 


13.43 


13.59 


252 


300 


35.0 


4.13 


13.40 


13.71 


13.80 


13.97 


253 


300 


35.0 


4.22 


13.13 


13.81 


13.92 


14 08 


254 


300 


35.0 


4.08 


13.34 


13.65 


13.80 


13.91 


255 


300 


34.0 


4.17 


13.76 


13.50 


13.67 


13.77 


256 


300 


33.0 


4.32 


13.39 


13.43 


13.55 


13.70 


257 


300 


33.0 


3.89 


12.56 


12.92 


13.07 


13.18 


258 


300 


31.5 


3.65 


12.57 


12.26 


12.46 


12.52 


259 


300 


33.0 


3.22 


12.04 


12.11 


12.23 


12.38 


260 


300 


32.0 


3.94 


12.40 


12.73 


12.82 


12.99 


261 


300 


33.0 


3.65 


12.35 


12.63 


12.83 


12.89 


262 


300 


32.0 


3.61 


12.28 


12.33 


12.46 


12.60 


263 


300 


32.5 


3.31 


12.13 


12.10 


12.22 


12.36 


264 


300 


32.9 


3.37 


12.28 


12.27 


12.47 


12.53 


265 


300 


33.0 


3.45 


12.17 


12.39 


12.59 


12.65 


266 


300 


32.0 


3.38 


11.98 


12.06 


12.22 


12.32 


267 


300 


31.4 


3.36 


12.07 


11.88 


12.10 


12.15 


268 


300 


30.2 


3.50 


11.89 


11.75 


11.85 


12.01 


269 


300 


31.2 


3.23 


11.70 


11.68 


11.74 


11.94 


270 


300 


30.5 


3.35 


11.57 


11.65 


11.85 


11.91 


271 


300 


30.4 


3.15 


11.58 


11.38 


11.61 


11.64 


272 


300 


31.3 


3.47 


11.96 


11.99 


12.22 


12:25 


273 


300 


32.0 


3.30 


11.70 


11.96 


12.10 


12.22 


274 


300 


31.6 


3.35 


11.38 


11.92 


12.10 


12.18 


275 


300 


30.1 


3.44 


11.26 


11.65 


11.73 


11.92 


276 


300 


31.0 


3.40 


11.38 


11.83 


11.98 


12.09 


277 


300 


30.2 


2.98 


11.40 


11.13 


11.25 


11.39, 


278 


300 


30.2 


3.20^ 


11.34 


11.39 


11.49 


11.65 


279 


301 


34.0 


4 22 


13.38 


13.56 


13.67 


13.83 


280 


301 


33.0 


415 


13.43 


13.23 


13.43 


13.49 


281 


301 


32.3 


4.66 


13.55 


13.67 


13.90 


13.93 


282 


301 


32.0 


4 44 


13.43 


13.33 


13.42 


13.59 


283 


301 


33.0 


4 29 


13.41 


13.40 


13.55 


13.66 


284 


301 


32.4 


4.72 


13.44 


13.76 


13.90 


14 03 


285 


301 


32.9 


4 22 


13.36 


13.29 


13.43 


13.55 


286 


301 


32.5 


4.37 


13.35 


13.37 


13.54 


13.63 


287 


301 


32.8 


4 61 


13.51 


13.73 


13.91 


14 00 


288 


301 


31.5 


4.72 


13.78 


13.54 


13.66 


13.80 


289 


301 


34.2 


4.16 


12.98 


13.54 


13.67 


13.81 


290 


301 


33.2 


4.40 


13.33 


13.58 


13.67 


13.84 


291 


301 


32.2 


4 31 


13.54 


13.22 


13.30 


13.49 


292 


301 


33.0 


442 


13.67 


13.55 


13.67 


13.82 



30 ESTIMATION OF TOTAL SOLIDS IN MILK. 

Table 16. — Comparative determinations of total solids in milk — Continued. 













Total solids. 








Specific 












Test 


Cow 


gravity 


Fat. 


















No. 


No. 


(Quevenne 
degrees). 


Gravi- 
metric. 


Babcock. 


Richmond. 


Fleisch- 
mann. 








Per cent. 


Per cent. 


Per cent. 


Per cent. 


Per cent. ■ 


293 


301 


33.7 


4.02 


13.47 


13.25 


13.31 


13.51 


294 


301 


33.5 


3.88 


13.41 


13.03 


13.19 


13.29 


295 


301 


34.2 


3.92 


13.27 


13.25 


13.31 


13.52 


296 


301 


34.0 


4.09 


13.99 


13.41 


13.55 


13.67 


297 


301 


34.0 


4 24 


13.31 


13.59 


13.67 


13.85 


298 


301 


33.5 


4.20 


12.83 


13.42 


13.55 


13.68 


299 


301 


33.0 


4.34 


13.37 


13. 46 


13.55 


13.72 


300 


301 


33.0 


3.72 


12.91 


12.71 


12.83 


12.98 


301 


301 


33.0 


4.23 


13.46 


13.33 


13.43 


13.59 


302 


301 


34.0 


4.25 


13.36 


13.60 


13.79 


13.86 


303 


301 


33.0 


4.32 


13.23 


13.43 


13.55 


13.70 


304 


301 


35.5 


4.11 


13.71 


13.81 


13.92 


14.07 


305 


301 


34.0 


3.89 


13.34 


13.17 


13.31 


13.43 


306 


301 


34.0 


3.56 


12.94 


12.77 


12.95 


13.04 


307 


301 


33.5 


3.90 


12.80 


13. 06 


13.19 


13.32 


308 


301 


34.0 


3.98 


13.02 


13.28 


13.43 


13.54 


309 


301 


31.7 


3.58 


12.54 


12.22 


12.34 


12.48 


310 


301 


31.1 


3.69 


12.37 


12.20 


12.34 


12.47 


311 


301 


33.8 


3.71 


12.05 


12.90 


13.07 


13.17 


312 


301 


32.0 


3.75 


12.36 


12.50 


12.70 


12.76 


313 


301 


33.0 


3.83 


12. 61 


12.85 


12.95 


13.11 


314 


301 


32.5 


3.80 


12.64 


12.69 


12.82 


12.95 


315 


301 


33.0 


3.85 


12.66 


12.87 


13.07 


13.13 


316 


301 


32.0 


3.71 


12.74 


12.45 


12.58 


12.72 


317 


301 


32.5 


3.75 


12.67 


12.63 


12.82 


12.89 


318 


301 


32.0 


4.01 


12.80 


12.81 


12.94 


13.08 


319 


301 


33.0 


3.75 


12.53 


12.75 


12.95 


13.01 


320 


301 


32.5 


4.12 


13.11 


13.07 


13.18 


13.33 


321 


301 


32.6 


3.86 


12.93 


12.78 


12.94 


13.05 


322 


301 


33.6 


4.24 


13.31 


13.49 


13.55 


13.75 


323 


301 


32.4 


4.09 


13.01 


13.01 


13.18 


13.27 


324 


301 


32.8 


4.00 


12.74 


13.00 


13.19 


13.26 


325 


301 


33.6 


3.71 


13.01 


12.85 


12.95 


13.12 


326 


301 


32.9 


3.65 


12.77 


12.61 


12.83 


12.87 


327 


301 


33.0 


3.76 


12.90 


12.76 


12.95 


13.03 


328 


301 


32.6 


4.07 


12.90 


13.03 


13.18 


13.30 


329 


301 


33.0 


3.77 


12.50 


12.77 


12.95 


13.04 


330 


301 


32.1 


4.00 


12.26 


12.83 


12.94 


13.09 


331 


301 


32.0 


3.96 


12.85 


12.75 


12.94 


13.02 


332 


301 


31.2 


4.16 


12.38 


12.79 


12.94 


13 06 


333 


301 


31.4 


3.76 


12.71 


12.36 


12.58 


12.63 


334 


301 


32.7 


3.76 


12.67 


12.69 


12.82 


12.95 


335 


301 


32.5 


4.07 


12.79 


13.01 


13.18 


13.27 


336 


301 


32.9 


3.55 


12.86 


12.49 


12.71 


12.75 


337 


301 


31.5 


3.84 


12.16 


12.48 


12.58 


12.75 


338 


301 


31.3 


3.61 


12.09 


12.16 


12.34 


12.42 


339 


301 


32.5 


3.67 


12.84 


12.53 


12.70 


12.79 


340 


301 


31.2 


3.71 


12.34 


12.25 


12.34 


12.52 


341 


302 


31.8 


4.88 


13.98 


13.81 


14.02 


14.07 


342 


302 


31.0 


4.73 


13.70 


13.43 


13.54 


13.69 


343 


302 


32.0 


3.92 


12.80 


12.70 


12.82 


12.97 


344 


302 


31.6 


4.08 


12.88 


12.80 


12.94 


13.06 


345 


302 


32.0 


4.47 


12.97 


13.36 


13.54 


13.63 


346 


302 


32.9 


4.11 


12.52 


13.16 


13.31 


13.42 


347 


302 


32.8 


4.48 


13.45 


13.58 


13.79 


13.84 


348 


302 


31.8 


4.48 


13.31 


13.33 


13.54 


13.59 


349 


302 


31.6 


4.71 


13.67 


13.55 


13.66 


13.82 


350 


302 


32.8 


4.07 


12.87 


13.08 


13.31 


13.35 


351 


302 


31.0 


4.71 


13.15 


13.40 


13.54 


13.67 


352 


302 


29.5 


5.18 


13.54 


13.59 


13.76 


13.85 


353 


400 


34.5 


4.48 


14.16 


14.00 


14.16 


14.26 


354 


400 


35.5 


4.07 


13.83 


13.76 


13.92 


14.02 


355 


400 


36.0 


3.88 


13.51 


13.66 


13.80 


13.92 


356 


400 


36.0 


4.03 


13.35 


13.84 


13.92 


14.10 


357 


400 


34.0 


4.33 


13.58 


13.70 


13.79 


13.96 


358 


400 


31.3 


3.95 


13.25 


12.57 


12.82 


12.83 


359 


400 


33.7 


3.92 


12.98 


13.13 


13.19 


13.39 


360 


400 


33.6 


4.17 


13.35 


13.40 


13.55 


13.67 


361 


400 


33.0 


4.13 


13.58 


13.21 


13.31 


13.47 


362 


400 


32.5 


4.31 


13.23 


13.30 


13.42 


13.56 


363 


400 


33.5 


3.99 


12.87 


13.16 


13.31 


13.43 


364 


400 


34.0 


3.54 


12.52 


12.75 


12.83 


13.01 


365 


400 


32.0 


3.30 


12.05 


11.96 


12. 10 


12.22 


366 


400 


33.0 


3.99 


12.81 


13.04 


13.19 


13.30 


367 


400 


34.0 


3.57 


12.11 


12.78 


12.95 


13.05 


368 


400 


32.8 


3.73 


12.96 


12.68 


12.83 


12. 94 


369 


400 


33.1 


3.53 


12.91 


12.51 


12.71 


12.78 



APPENDIX. 31 

Table 16. — Comparative determinations of total solids in milk — Continued. 













Total solids. 








Specific 












Test 


Cow 


gravity 


Fat. 


















No. 


No. 


(Quevenne 
degrees). 


Gravi- 
metric. 


Babcock. 


Richmond. 


Fleisch- 
mann. 








Per cent. 


Per cent. 


Per cent. 


Per cent. 


Per cent. 


370 


400 


35.1 


3.92 


13.28 


13.48 


13.56 


13.74 


371 


400 


34.0 


3.78 


12.94 


13.04 


13.19 


13.30 


372 


400 


35.0 


3.55 


13.11 


13.01 


13.20 


13.27 


373 


400 


34.6 


3.62 


13.17 


12.99 


13.08 


13.26 


374 


400 


33.4 


3.72 


13.01 


12.81 


12.95 


13.08 


375 


400 


33.7 


3.61 


13.01 


12.76 


12.83 


13.02 


376 


400 


34.3 


3.79 


13.00 


13.12 


13.32 


13.39 


377 


400 


35.0 


3.52 


12. 69 


12.97 


13.08 


13.24 


378 


400 


34.0 


4.07 


12.99 


13.38 


13.55 


13.65 


379 


400 


34.0 


3.85 


13.18 


13.12 


13.31 


13.38 


380 


400 


33.2 


3.95 


12.97 


13.04 


13.19 


13.30 


381 


400 


33.7 


3.53 


12.88 


12.66 


12.71 


12.92 


382 


400 


34.4 


3.90 


13.26 


13.28 


13.44 


13.54 


383 


400 


34.6 


3.96 


13.34 


13.40 


13.56 


13.66 


384 


400 


34.7 


3.53 


12.85 


12.94 


12.96 


13.17 


385 


400 


32.6 


3.43 


12.40 


12.27 


12.34 


12.53 


386 


400 


32.0 


3.91 


13.03 


12.69 


12.82 


12.96 


387 


400 


34.0 


4.52 


13.48 


13.92 


14.03 


14.19 


388 


402 


36.0 


4.49 


14.06 


14.39 


14.52 


14.65 


389 


402 


35.0 


5.14 


14.32 


14. 92 


15.00 


15.18 


390 


402 


32.9 


4.48 


13.62 


13.60 


13.79 


13.87 


391 


402 


32.6 


4.08 


12.94 


13.05 


13. 18 


13.31 


392 


402 


32.8 


4.31 


13.18 


13.37 


13.55 


13.64 


393 


402 


33.0 


4.20 


13.34 


13.29 


13.43 


13.55 


394 


402 


34.5 


4.20 


13.41 


13.67 


13.80 


13.93 


395 


402 


34.0 


3.96 


13.23 


13.25 


13.43 


13.52 


396 


402 


34.0 


4.21 


13.46 


13.55 


13.67 


13.82 


397 


402 


33.5 


3.92 


12.91 


13.08 


13.19 


13.34 


398 


402 


32.5 


3.77 


12.83 


12.65 


12.82 


12.91 


399 


402 


34.0 


3.99 


13.07 


13.29 


13.43 


13.55 


400 


402 


33.7 


3.61 


12.78 


12.76 


12.83 


13.02 


401 


402 


34.0 


4.03 


13.41 


13.34 


13.43 


13.60 


402 


402 


34.4 


3.69 


13.01 


13.03 


13.20 


13.29 


403 


402 


34.0 


3.86 


13.06 


13.13 


13.31 


13.40 


404 


402 


33.0 


3.92 


13.06 


12.95 


13.07 


13.22 


405 


402 


34.0 


3.84 


13.26 


13.11 


13.19 


13.37 


406 


402 


34.4 


3.80 


13.21 


13.16 


13.32 


13.42 


407 


402 


33.4 


3.80 


13.11 


12.91 


13.07 


13.17 


408 


402 


33.7 


3.79 


13. 15 


12.97 


13.07 


13.24 


409 


402 


34.0 


3.93 


12.94 


13. 22 


13.31 


13.48 


410 


402 


34.4 


3.78 


12.86 


13.14 


13.32 


13.40 


411 


402 


33.6 


4.16 


12.94 


13.39 


13.55 


13.66 


412 


402 


32.7 


3.94 


13.10 


12.90 


12.94 


13.17 


413 


402 


32.7 


4.12 


12.69 


13.12 


13.18 


13.38 


414 


402 


33.4 


3.76 


13.02 


12.86 


13.07 


13.13 


415 


402 


34.5 


4.09 


13.26 


13.53 


13.68 


13.80 


416 


402 


34.0 


4.20 


13.46 


13.54 


13.67 


13.80 


417 


403 


35.8 


4.06 


13.63 


13.82 


14.04 


14.08 


418 


403 


36.0 


3.53 


12.85 


13.24 


13.32 


13.50 


419 


403 


33.8 


3.45 


12.42 


12.59 


12.83 


12.85 


420 


403 


33.4 


3.27 


12. 49 


12.27 


12.47 


12.54 


421 


403 


33.3 


3.35 


12.21 


12.35 


12.59 


12.61 


422 


403 


32.7 


3.35 


12.07 


12.20 


12.34 


12.46 


423 


403 


33.3 


3.45 


12.12 


12.47 


12.71 


12.73 


424 


403 


32.0 


3.36 


12.22 


12.03 


12.22 


12.30 


425 


403 


32.0 


3.33 


11.61 


12.00 


12.10 


12.26 


426 


403 


32.3 


2.96 


11.86 


11.63 


11.86 


11.89 


427 


403 


32.9 


3.16 


11.53 


12.02 


12.23 


11.28 


428 


403 


33.6 


3.26 


12.00 


12.31 


12.47 


12.58 


429 


403 


32.3 


3.01 


11.32 


11.69 


11.86 


11.95 


430 


403 


31.6 


3.19 


11.40 


11.73 


11.86 


11.99 



Note.— Cows Nos. 4, 99, and 118 are Jerseys; Nos. 205, 206, and 209 are Holstein- 
Friesians; Nos. 300, 301, and 302 are Ayrshires, and Nos. 400, 402, and 403 are Shorthorns. 



o 



